Working like a scientist
By the end of this chapter you will be able to
- Ask a question that I can find out the answer to, and say how I could find out
- Look closely and notice details, using a hand lens, a ruler and a timer
- Set up a fair test in which only one thing changes
- Sort things into groups using one rule or two rules
- Suggest an idea from what I notice, and say how I could test it
- Record counts in a tally chart, a table, a pictogram or a bar chart, and compare them
You should already know
- Asking simple questions and using simple tools (Year 1, Chapter 1)
- Counting objects, and counting in tens and ones (Year 1 and Year 2 Maths)
Where this leads
- Living, dead and never alive (Chapter 2)
- Changing shape: a fair test with materials (Chapter 10)
National Curriculum for England, Key Stage 1 science, Year 2. Content: Ask simple questions and recognise that they can be answered in different ways, Observe closely, using simple equipment: a hand lens, a ruler and a timer, Perform simple tests and see that a fair test changes only one thing, Identify and classify things using one or two rules, Use observations and ideas to suggest answers, and check them by testing, Gather and record data using tally charts, tables, pictograms and bar charts.
Exercise P Do you remember?
Method. Think about which tool counts the seconds and minutes.
- Think about the job. We want a tool for time, not for length.time
- Choose the tool. A timer counts how long something takes.timer: time
- Write the answer. timer
Check. A ruler measures length, so it is not the answer. ✓
Watch out. A ruler measures length. A timer measures time.
Method. Think about the legs a dog uses to walk.
- Look at the dog. A dog walks on four legs.four legs
- Count the legs. Count the two front legs and the two back legs.2 + 2 = 4
- Write the answer. 4
Check. Count them one at a time: 1, 2, 3, 4. ✓
Watch out. Count the back legs too.
Method. Find each count, then add them all together.
- Write down each count. Each count is one row.blue 6, red 3
- Add the counts together. Add them all, so none is missed.6 + 3 = 9
- Write the answer. 9
Check. Add them again, starting from the last count, and you get 9. ✓
Watch out. Make sure every row is in your total, and no row is counted twice.
Method. Look for the one that is different from the other three.
- Look at the cat, the dog and the rabbit. Each of these has four legs.cat, dog, rabbit: four legs
- Look at the fish. A fish has no legs. It has fins.fish: no legs
- Write the answer. fish
Check. Three things have four legs, and one does not. ✓
Watch out. Look for what is different, not for what is the same.
Method. Think about which animal is covered in fur.
- Think about each animal. A cat is covered in fur. A bird has feathers. A fish has scales.cat: fur
- Find the one with fur. Only the cat has fur.cat
- Write the answer. cat
Check. Feathers and scales are not fur. ✓
Watch out. A bird has feathers. A fish has scales.
Asking good questions
Scientists are curious. They ask questions about the world. Then they find out the answers.
A good science question is one we can find out. We can find out by looking, by measuring, by testing an idea, or by using a book.
Some questions can be answered in more than one way.
Key ideas
- A science question is one we can find out.
- We can look, measure, test or use a book.
- Some questions can be answered in more than one way.
- An opinion, such as “Which is the best?”, is not a science question.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.How many wheels does a bike have?
- Pick the way. We can see the wheels, so we can count them.Way: look
- Write the answer. look
Check. Count the wheels one at a time. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.How long is this shell?
- Pick the way. A length needs a ruler. We line the shell up with the ruler.Way: measure
- Write the answer. measure
Check. Put the 0 mark at one end, and read the other end. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.Do snails move faster on wet paper or dry paper?
- Pick the way. We can try the snail on each kind of paper, and see which one is faster.Way: test
- Write the answer. test
Check. Use the same snail, and time it on each paper. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Watch out
Watch out: a question such as “Which colour is the nicest?” is an opinion. We cannot test an opinion, so it is not a science question.
Try it at home (with a grown-up). Go on a short walk, or look out of a window, with a grown-up. Each of you asks one question about something you see. Choose one question that you can find out by looking, measuring or testing. Decide together how you could find out.
Exam tip
Grown-up tip. When your child asks “why?”, help them turn it into a question you can find out together. Ask: “How could we find out?” Let them choose look, measure, test or book.
Exercise 1A Asking questions and ways to find out
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.How tall is the door?
- Pick the way. A height is a length, so a ruler or a tape measure can measure it.Way: measure
- Write the answer. measure
Check. Stand the ruler on the floor, and read the mark at the top of the door. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.How many legs does a cat have?
- Pick the way. We can see the cat, so we can count its legs.Way: look
- Write the answer. look
Check. Count the legs one at a time. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.Which cup holds more water?
- Pick the way. We can fill each cup and see which one holds more.Way: test
- Write the answer. test
Check. Use the same amount of water to fill each cup. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.What do hedgehogs eat?
- Pick the way. We cannot see what a hedgehog eats, so we look in a book about hedgehogs.Way: book
- Write the answer. book
Check. Ask a grown-up to help you find a book or a website for children. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.How heavy is a teddy bear?
- Pick the way. Heavy means how much it weighs, so we use scales.Way: measure
- Write the answer. measure
Check. Put the teddy on the scales and read the weight. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.Which pencil is longer?
- Pick the way. Length is measured with a ruler, so Ali can measure each pencil.Way: measure
- Write the answer. measure
Check. Put both pencils on a ruler, starting at 0. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Ask which question asks for a number that we can measure.
- Read question A. It asks how tall the tree is. A ruler or a tape measure can find that out.A: how tall
- Read question B. It asks which tree is prettiest. That is an opinion.B: an opinion
- Write the answer. A
Check. Measure the tree, and you have an answer to question A. ✓
Watch out. An opinion is what someone likes. A measurement is a number.
Method. Ask which question can be found out, and which one is only what someone likes.
- Read question A. We can count the petals on a daisy, so this can be found out.A: can be found out
- Read question B. The best bird depends on what someone likes, so there is no one right answer.B: an opinion
- Write the answer. B
Check. Question A has a number as the answer. Question B does not. ✓
Watch out. Ask: is there one right answer that we can find out?
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.Are all the cubes the same size?
- Pick the way. We can look at the cubes and compare them.Way: look
- Write the answer. look
Check. Put two cubes side by side and compare them. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.How long is a worm?
- Pick the way. A length needs a ruler.Way: measure
- Write the answer. measure
Check. Lay the worm along the ruler from 0. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.Which of two worms moves faster?
- Pick the way. We can time each worm on the same path.Way: test
- Write the answer. test
Check. Use the same path and the same timer. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.What do worms eat?
- Pick the way. We look for the answer in a book.Way: book
- Write the answer. book
Check. Ask a grown-up to find a book about worms. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think of something you could try, then turn it into a question.
- Choose something to test. A snail can be tested on wet and dry paper.wet and dry paper
- Make it a question. Start with “Do” or “Which” so it can be tested.Do snails like wet paper?
- Check it. We can test it, and count or time the snail. Also accept: Which paper do snails move on faster?Do snails like wet paper?
Check. A test can answer it, so it is a science question. ✓
Watch out. The question must be one that a test can answer.
Observing closely
To observe means to look closely and notice details. We look, listen and feel, so we notice more. We describe what we see, one thing at a time.
Scientists use simple tools to see more. A hand lens makes small things look bigger. A ruler measures length in centimetres (cm). A timer measures how long something takes.
Key ideas
- To observe is to look closely and notice details.
- A hand lens makes small things look bigger.
- Measure length in centimetres, starting at the 0 mark.
- A timer measures how long something takes.
- Never look at the Sun through a hand lens.
Method. Think about which tool makes small things look bigger.
- Read the question. We want to see tiny parts, which are very small.tiny parts
- Think about each tool. A hand lens makes small things look bigger. A ruler and a timer do not.hand lens: bigger
- Write the answer. hand lens
Check. Look at the flower through a hand lens, and the parts look bigger. ✓
Watch out. Hold the hand lens close to the flower, and move it slowly.
Method. Put the 0 mark at one end of the object. Then read the mark at the other end.
- Put the 0 mark at the end of the stick. Starting at 0 makes the count start in the right place.stick starts at 0
- Read the mark at the other end. The number there is how long it is.It ends at 5
- Write the length, with the unit. We measure length in centimetres, written cm.5 cm
Check. Count along the ruler from 0 to 5, one centimetre at a time. ✓
Watch out. Start at 0, not at the end of the ruler. Otherwise the answer will be wrong.
Method. Read the start time and the stop time. Then count the minutes between them.
- Read the start time. The timer starts at this time.2:00
- Read the stop time. The timer stops at this time.2:05
- Count the minutes from start to stop. Count on one minute at a time.1 2 3 4 5
- Write the answer. 5
Check. Count back from the stop time to the start time. You get 5 minutes. ✓
Watch out. The minute hand goes all the way round the clock once in an hour. Count minutes, not hours.
Watch out
Watch out: start measuring at the 0 mark, not at the end of the ruler. If you start at a different number, your answer will be wrong.
Try it at home (with a grown-up). With a grown-up, look at a leaf or a flower through a hand lens. Draw what you see, and count the parts you can see. Never look at the Sun through a hand lens. Wash your hands afterwards.
Exam tip
Grown-up tip. Let your child hold the hand lens. Ask: “What can you see now that you could not see before?” Let them say one thing at a time.
Exercise 1B Using a hand lens, a ruler and a timer
Method. Think about which tool makes small things look bigger.
- Read the question. We want to see tiny parts.tiny parts
- Choose the tool. A hand lens makes small things look bigger.hand lens: bigger
- Write the answer. hand lens
Check. A ruler measures length, and a timer measures time. Neither makes things bigger. ✓
Watch out. Use a hand lens to look, and never use it to look at the Sun.
Method. Think about which tool measures length.
- Read the question. We want to measure a length: how long the worm is.how long
- Choose the tool. A ruler measures length in centimetres.ruler: length
- Write the answer. ruler
Check. Lay the worm along the ruler and read the length. ✓
Watch out. A timer measures time, not length.
Method. Put the 0 mark at one end of the object. Then read the mark at the other end.
- Put the 0 mark at the end of the worm. Starting at 0 makes the count start in the right place.worm starts at 0
- Read the mark at the other end. The number there is how long it is.It ends at 6
- Write the length, with the unit. We measure length in centimetres, written cm.6 cm
Check. Count along the ruler from 0 to 6, one centimetre at a time. ✓
Watch out. Start at 0, not at the end of the ruler. Otherwise the answer will be wrong.
Method. Measure each bar from 0. Then compare the two numbers.
- Measure A. Start at 0 and read the end.A = 4 cm
- Measure B. Start at 0 and read the end.B = 8 cm
- Compare the two lengths. The bigger number is the longer bar.8 is bigger than 4
- Write the answer. B is longer by 4 cm.B
Check. Count the difference on the ruler: 8 − 4 = 4 cm. ✓
Watch out. Compare the two numbers, not how big the bars look.
Method. Read the start time and the stop time. Then count the minutes between them.
- Read the start time. The timer starts at this time.3:00
- Read the stop time. The timer stops at this time.3:04
- Count the minutes from start to stop. Count on one minute at a time.1 2 3 4
- Write the answer. 4
Check. Count back from the stop time to the start time. You get 4 minutes. ✓
Watch out. The minute hand goes all the way round the clock once in an hour. Count minutes, not hours.
Method. Find the two times. Then take the smaller time away from the bigger time.
- Read the two times. Ali: 4 minutes. Sam: 9 minutes.4 minutes, 9 minutes
- Take the smaller time away. The difference is how many more minutes.9 − 4 = 5
- Write the answer. 5
Check. Add the difference back on: 4 + 5 = 9. ✓
Watch out. Take the smaller number away from the bigger one.
Method. An observation is something we can see, hear or measure.
- Read (a). We can look at the leaf and see that it is green.a: we can see it
- Read (b). We cannot see that a leaf is sad. That is a guess.b: a guess
- Write the answer. a
Check. Look at the leaf, and you can see its colour. ✓
Watch out. An observation says what you see. A guess says what you think.
Method. Think about which sentence we can see, and which one we cannot see.
- Read (a). We can see the colour of the shell.a: we can see it
- Read (b). We cannot see whether a snail is hungry, so it is a guess.b: a guess
- Write the answer. b
Check. A guess can be tested later. An observation is already seen. ✓
Watch out. Hungry is a feeling. We cannot see it.
Method. Count the eggs once each. Touch each one as you count it.
- Count them one at a time. Say each number as you touch one.1 2 3 4
- Read the last number. The last number is how many there are.4
- Write the answer. 4
Check. Count them again from the other end. You get 4 again. ✓
Watch out. Move each one to one side as you count it, so you do not count it twice.
| Leaf | Length (cm) |
|---|---|
| Leaf A | 6 |
| Leaf B | 9 |
| Leaf C | 4 |
Method. Compare the numbers. The biggest number is the most.
- Write down each number. Put each number next to its name.Leaf A 6, Leaf B 9, Leaf C 4
- Find the biggest number. 9 is the biggest number.biggest: 9
- Write the answer. Leaf B has 9.Leaf B
Check. Every other number is smaller than 9. ✓
Watch out. Check every number, not only the first two.
Method. Think about what a measurement tells us.
- Read what Ali said. The word “big” does not say how big.big: no number
- Think about measuring. A ruler gives a number, so we can compare it with other leaves.a number in cm
- Write the answer. a number
Check. A number in centimetres can be checked by anyone. ✓
Watch out. A measurement is a number, so it can be compared.
Performing simple tests
A test helps us find the answer to a question. We try something, and we see what happens.
In a fair test, we change only one thing. We keep everything else the same.
Then we count or measure the results, and we write them down. We can compare the results, and we can test again to check them.
Key ideas
- A fair test changes only one thing.
- Keep everything else the same.
- Count or measure the results, and write them down.
- Repeat the test to check your results.
Method. Compare the numbers. The biggest number is the most.
- Write down each number. Put each number next to its name.Cup A 8, Cup B 5, Cup C 10
- Find the biggest number. 10 is the biggest number.biggest: 10
- Write the answer. Cup C has 10.Cup C
Check. Every other number is smaller than 10. ✓
Watch out. Check every number, not only the first two.
Method. Find each count. Then take the smaller count away from the bigger count.
- Read the count for Cup C. There are 10.Cup C: 10
- Read the count for Cup B. There are 5.Cup B: 5
- Take the smaller count away from the bigger one. The difference is how many more.10 − 5 = 5
- Write the answer. 5
Check. Add the difference back on: 5 + 5 = 10. ✓
Watch out. Take the smaller number away from the bigger one, not the other way round.
Method. Count how many things change in the test.
- Find the things that change. Ali changes the cup and the cubes.cup and cubes
- Count the changes. A fair test changes only one thing.two changes
- Write the answer. no
Check. If two things change, we cannot tell which one made the difference. ✓
Watch out. Change one thing only, and keep the rest the same.
Watch out
Watch out: if you change two things at once, you cannot tell which one made the difference.
Try it at home (with a grown-up). With a grown-up, find three cups of different sizes. Put the same small bricks or cubes into each cup, one at a time, until the cup is full. Count the bricks in each cup and write down the counts. Which cup held the most?
Exam tip
Grown-up tip. Let your child count the bricks out loud. Ask: “What did we keep the same? What did we change?” Then ask them to do the test again to check.
Exercise 1C Simple tests and fair tests
Method. Think about the one thing that is different from one test to the next.
- Look at the test. Each test uses a different cup.different cups
- Check the cubes. The same kind of cube was used, so the cubes did not change.same cubes
- Write the answer. the cup
Check. Only the cup changed, so the test is fair. ✓
Watch out. Name the one thing that changed, not the things that stayed the same.
Method. Compare the numbers. The biggest number is the most.
- Write down each number. Put each number next to its name.Boat 1 7, Boat 2 11, Boat 3 5
- Find the biggest number. 11 is the biggest number.biggest: 11
- Write the answer. Boat 2 has 11.Boat 2
Check. Every other number is smaller than 11. ✓
Watch out. Check every number, not only the first two.
Method. Compare the numbers. The smallest number is the fewest.
- Write down each number. Put each number next to its name.Boat 1 7, Boat 2 11, Boat 3 5
- Find the smallest number. 5 is the smallest number.smallest: 5
- Write the answer. Boat 3 has 5.Boat 3
Check. Every other number is bigger than 5. ✓
Watch out. Check every number, not only the first two.
Method. Find each count. Then take the smaller count away from the bigger count.
- Read the count for Boat 2. There are 11.Boat 2: 11
- Read the count for Boat 1. There are 7.Boat 1: 7
- Take the smaller count away from the bigger one. The difference is how many more.11 − 7 = 4
- Write the answer. 4
Check. Add the difference back on: 7 + 4 = 11. ✓
Watch out. Take the smaller number away from the bigger one, not the other way round.
Method. Count the cubes once each. Touch each one as you count it.
- Count them one at a time. Say each number as you touch one.1 2 3 4 5 6 7
- Read the last number. The last number is how many there are.7
- Write the answer. 7
Check. Count them again from the other end. You get 7 again. ✓
Watch out. Move each one to one side as you count it, so you do not count it twice.
Method. Check how many things change in the test.
- Find the thing that changes. Ben changes only the jar.jar
- Check the other things. The cubes are the same, so they are kept the same.cubes: same
- Write the answer. Only one thing changes, so the test is fair.yes
Check. One thing changed, and the rest was kept the same. ✓
Watch out. Check that only one thing is different.
Method. Count how many things change.
- Find the things that change. The boat changes, and the water changes too.boat and water
- Count the changes. A fair test changes only one thing.two changes
- Write the answer. no
Check. Use the same water each time to make it fair. ✓
Watch out. The water must be the same in each tub.
Method. Think about which thing we are testing.
- Look at the test. We are testing the boats, so the boat changes.the boat changes
- Keep the rest the same. The water must stay the same, so the test is fair.water: same
- Write the answer. the amount of water
Check. Use the same amount of water in each tub. ✓
Watch out. Keep everything the same except the one thing you test.
Method. Look at the three results. Find the number that happens most.
- Write the three results. Each test gives one result.7, 8, 7
- Find the number that happens twice. The number 7 happens twice. The number 8 happens once.7 happens 2 times
- Write the answer. 7
Check. Two of the three tests gave 7. ✓
Watch out. Repeating a test helps us see which result is usual.
Method. Find each count, then add them all together.
- Write down each count. Each count is one row.Boat 1 7, Boat 3 5
- Add the counts together. Add them all, so none is missed.7 + 5 = 12
- Write the answer. 12
Check. Add them again, starting from the last count, and you get 12. ✓
Watch out. Make sure every row is in your total, and no row is counted twice.
Method. Choose one thing to change. Then say what must stay the same.
- Choose the one thing to change. Change the cup, and nothing else.change: the cup
- Choose the things to keep the same. Keep the cubes the same, and count them the same way.keep: the cubes
- Write the answer. the cup
Check. The cup is the one thing we change. The cubes stay the same. ✓
Watch out. Only one thing changes in a fair test.
Identifying and classifying
To classify means to sort things into groups. We sort them by a rule. A rule is about a feature, such as “has fur”.
Some rules use two features, such as “can fly” and “has four legs”. Each thing is checked against each rule.
To identify a thing, we look for its features. Then we match them to a group.
Key ideas
- Sort things by a rule about their features.
- Check each thing against the rule, one at a time.
- Some rules use two features, so check two things.
- Name each group by its rule.
Method. Check each animal against the rule: does it have four legs?
- Check the dog and the horse. Each of these walks on four legs.dog: four, horse: four
- Check the bird and the fish. A bird has two legs, and a fish has no legs.bird: two, fish: none
- Write the answer. dog and horse
Check. Two animals have four legs, and two do not. ✓
Watch out. Check every animal, not just the first two.
Method. Check each animal against the rule: does it have fur?
- Check the cat and the rabbit. Both are covered in fur.cat and rabbit: fur
- Check the bird and the fish. A bird has feathers. A fish has scales. Neither has fur.bird and fish: no fur
- Write the answer. has fur: cat, rabbit. no fur: bird, fish.
Check. Each animal is in one group only: 2 + 2 = 4 animals. ✓
Watch out. Feathers and scales are not fur.
Method. Check each animal against both rules.
- Check the first rule: can it fly? A bird and a butterfly can fly. A spider and a cat cannot.bird, butterfly: fly
- Check the second rule: six legs? A butterfly has six legs. A bird has two, a spider has eight and a cat has four.butterfly: six
- Write the answer. Only the butterfly is in both groups.butterfly
Check. Only one animal passes both rules. ✓
Watch out. Check each animal against both rules, not just the first.
Watch out
Watch out: check the rule, not the colour or the size. A small cat and a big dog both have four legs.
Try it at home (with a grown-up). Sort the socks in a drawer into “striped” and “not striped”, with a grown-up. Then sort them again by a different rule, such as “long” and “short”. Talk about which rule was easier.
Exam tip
Grown-up tip. Ask your child to choose the rule before they sort. Then ask: “Can you think of a second rule?” Sorting is about noticing what things have in common.
Exercise 1D Sorting and classifying
Method. Check each animal: does it have legs?
- Check the cat and the dog. Both walk on four legs.cat and dog: four legs
- Check the fish. A fish swims with fins, and it has no legs.fish: no legs
- Write the answer. fish
Check. Two animals have legs, and one does not. ✓
Watch out. Look for the animal that has no legs at all.
Method. Check each animal: can it fly?
- Check the bird and the butterfly. Most birds and butterflies can fly.bird, butterfly: fly
- Check the cat and the fish. A cat walks and a fish swims. They cannot fly.cat, fish: no
- Write the answer. bird and butterfly
Check. Two of the four animals can fly. ✓
Watch out. Check every animal, one at a time.
Method. Count the legs of each animal.
- Check the spider. A spider has eight legs.spider: eight
- Check the penguin and the butterfly. A penguin has two legs. A butterfly has six legs.penguin: two, butterfly: six
- Check the dog. A dog has four legs.dog: four
- Write the answer. dog
Check. Only the dog has four legs. ✓
Watch out. Count the legs one at a time. Do not guess.
Method. Think about which animal is covered in feathers.
- Check the cat, the dog and the rabbit. These are covered in fur.fur, not feathers
- Check the penguin. A penguin is a bird, and birds have feathers.penguin: feathers
- Write the answer. penguin
Check. Feathers are not fur. Only the penguin has feathers here. ✓
Watch out. Feathers are soft and light. Fur is thick and furry.
Method. Check each animal, then count the ones that can fly.
- Check each animal. A bird, a butterfly and a bee can fly. A cat and a dog cannot.fly: bird, butterfly, bee
- Count the animals that can fly. Count each one once.1, 2, 3
- Write the answer. 3
Check. Two animals cannot fly, and 3 + 2 = 5 animals. ✓
Watch out. Count only the ones that fit the rule.
Method. Check the number of legs for each animal.
- Check the cat, the dog and the horse. Each has four legs.four legs each
- Check the bird. A bird has two legs.bird: two legs
- Write the answer. The bird is the odd one out.bird
Check. Three animals have four legs, and one does not. ✓
Watch out. Look for what is different from the other three.
Method. Read the number of toys without wheels from the picture, then count them.
- Read the groups. The group with no wheels shows the toys that do not have wheels.no wheels: 4
- Count the toys with no wheels. Count each one once.1, 2, 3, 4
- Write the answer. 4
Check. 6 + 4 = 10 toys in all. ✓
Watch out. Check that the two groups add up to the total.
Method. Check the legs of each animal in each pair.
- Check choice a. A cat and a dog both walk on four legs.a: four and four
- Check choice b. A bird has two legs, and a fish has no legs.b: two and none
- Write the answer. a
Check. Only the first pair has four legs each. ✓
Watch out. Check both animals in the pair, not just one.
Method. Think about which thing can hold something inside it.
- Check the tin, the jar and the bottle. Each one can hold something inside it.container
- Check the ball. A ball cannot hold things inside it.ball: not a container
- Write the answer. ball
Check. Three things are containers, and one is not. ✓
Watch out. Think about the job each thing does.
Method. Think about which animal has scales.
- Check the fish. Most fish have scales on their bodies.fish: scales
- Check the bird. A bird has feathers, not scales.bird: feathers
- Write the answer. fish
Check. Scales and feathers are different. ✓
Watch out. Feathers and scales are not the same.
Method. Think about which animal carries a shell.
- Check the snail. A land snail carries a shell on its back.snail: shell
- Check the dog. A dog does not have a shell.dog: no shell
- Write the answer. snail
Check. Only the snail has a shell. ✓
Watch out. A shell is hard and covers the body.
Method. Think about one animal with fur, and check the rule.
- Think of an animal with fur. A cat has fur, and a cat cannot fly.cat: fur, no fly
- Check the claim. One animal with fur cannot fly, so the claim is not true for all.not all
- Write the answer. no
Check. One counter-example shows the claim is wrong. ✓
Watch out. One example that does not fit is enough to show that a claim is wrong.
Using observations and ideas to suggest answers
Scientists notice things, and then they suggest an answer. This suggested answer is an idea. It is based on what we have noticed.
An idea must be tested before we know it is true. We test it, then count or measure the results. Then we decide if the idea was right.
Key ideas
- An observation is what we notice.
- An idea is a suggested answer, based on what we notice.
- A good idea can be tested.
- We decide if the idea was right by looking at the results.
Method. Notice the beak, and think about what it might be good for.
- Notice the beak. The beak is short and thick, so it is good for cracking seeds.short, thick beak
- Suggest an idea. The bird might eat seeds. This is an idea, not a fact yet.idea: seeds
- Check the choices. A bird cannot eat bricks, so choice c is not right.bricks: no
- Write the answer. a
Check. Test the idea by putting seeds on a bird table, with a grown-up, and watching. ✓
Watch out. An idea is not a fact until we test it.
Method. Think about what happens when warm breath meets cold air.
- Notice what we see. Breath looks like a cloud on a cold day.cloud on a cold day
- Think about the air. Warm breath cools when it meets cold air, and it looks like a small cloud.warm meets cold
- Check the choices. The air is not hot on a cold day, and the sun is not the cause.a and c: no
- Write the answer. b
Check. Breathe out onto a cold window with a grown-up to see it. ✓
Watch out. A suggested answer is only an idea, so it must be tested.
Method. Find the test that compares damp and dry places.
- Read choice a. It puts the snails in damp and dry places, and it watches them.a: compares
- Read choice b. Giving a name does not test where snails like to be.b: does not test
- Write the answer. A fair test compares damp and dry, and counts the snails in each.a
Check. Count the snails on each tray after an hour, and compare. ✓
Watch out. A good test changes one thing: the damp or the dry tray.
Watch out
Watch out: an idea is not a fact. Always test an idea before you say it is true.
Try it at home (with a grown-up). With a grown-up, watch a bird in the garden for 5 minutes. Write down what you see. Suggest one idea about why the bird chooses to land near the bushes. Watch again another day to check your idea.
Exam tip
Grown-up tip. Before you watch, ask your child: “What do you think we will see? Why?” Afterwards, ask: “Was our idea right?”
Exercise 1E Ideas and observations
Method. An observation is something we can see now.
- Read (a). We can look at the rabbit and see its ears.a: we can see it
- Read (b). We cannot see how a rabbit will feel later. That is a guess.b: a guess
- Write the answer. a
Check. Look at the rabbit now, and you can see its ears. ✓
Watch out. An observation is about now. A guess is about later.
Method. An idea we can test can be counted or measured.
- Read (a). Whether birds are the best is an opinion, so we cannot test it.a: an opinion
- Read (b). We can put a snail on dry paper and time it, then compare.b: can be timed
- Write the answer. b
Check. We can measure the speed on dry and wet paper. ✓
Watch out. A good idea can be tested.
Method. Think about what the curled-up shape does for the hedgehog.
- Notice what the hedgehog does. It curls up into a ball, so the spines face outward.curled up, spines out
- Choose the idea that fits. Curling up can keep the soft parts of the body safe.a: protects itself
- Write the answer. Choice b is not a reason that can be tested.a
Check. We could test this by watching what happens when something moves close by. ✓
Watch out. A good idea gives a reason we can check.
Method. Think about the one thing that makes the test different.
- Look at the test. We compare wet paper and dry paper.wet and dry paper
- Keep the rest the same. The snail, the path and the timer stay the same.same snail and timer
- Write the answer. the paper
Check. Only the paper changes, so the test is fair. ✓
Watch out. Change the paper, and keep the snail the same.
Method. Compare the numbers. The biggest number is the most.
- Write down each number. Put each number next to its name.Pot A 2, Pot B 5, Pot C 3
- Find the biggest number. 5 is the biggest number.biggest: 5
- Write the answer. Pot B has 5.Pot B
Check. Every other number is smaller than 5. ✓
Watch out. Check every number, not only the first two.
Method. Think about what the shade does to the puddle.
- Notice the puddle. The puddle is still wet, because it is in the shade.shade: still wet
- Choose the idea that fits. Shade keeps the puddle cooler, so the water dries more slowly.a: cooler, slower
- Write the answer. A frog does not explain why the water is still wet.a
Check. We can test this with two puddles, one in the shade and one in the sun. ✓
Watch out. A good idea should explain what we noticed.
Method. Find the test that compares damp soil with dry soil.
- Read choice a. It compares damp and dry soil, and it watches the worms.a: compares
- Read choice b. Naming the worms does not tell us where they like to be.b: no test
- Write the answer. a
Check. Count the worms in each soil after a while, and compare. ✓
Watch out. A test must compare two things.
Method. Think about what writing results down helps us do.
- Read (a). Written results stay the same, so we can compare them.a: compare later
- Read (b). Writing results is not about the room.b: not the reason
- Write the answer. a
Check. A written record helps us remember and compare. ✓
Watch out. Recording helps us find patterns.
| Paper | cm moved |
|---|---|
| Wet paper | 10 |
| Dry paper | 4 |
Method. Find each count. Then take the smaller count away from the bigger count.
- Read the count for Wet paper. There are 10.Wet paper: 10
- Read the count for Dry paper. There are 4.Dry paper: 4
- Take the smaller count away from the bigger one. The difference is how many more.10 − 4 = 6
- Write the answer. 6
Check. Add the difference back on: 4 + 6 = 10. ✓
Watch out. Take the smaller number away from the bigger one, not the other way round.
Method. Find each count, then add them all together.
- Write down each count. Each count is one row.Pot A 2, Pot B 5, Pot C 3
- Add the counts together. Add them all, so none is missed.2 + 5 + 3 = 10
- Write the answer. 10
Check. Add them again, starting from the last count, and you get 10. ✓
Watch out. Make sure every row is in your total, and no row is counted twice.
Method. Think about which way gives us counts that we can compare.
- Read (a). We count the birds on cold and warm days, so we can compare.a: counts
- Read (b). A friend’s answer is not a test of the birds.b: not a test
- Write the answer. a
Check. Compare the counts on the cold days and the warm days. ✓
Watch out. A fair check compares counts, and does not just ask someone.
Gathering and recording data
When we find things out, we gather data. Data is the information we collect, such as counts. Then we record it, so we can remember it and compare it.
A tally chart uses marks. Five marks make a group: four going up and one going across them.
A table puts the results in rows, with a heading. A pictogram uses one picture for each thing. A bar chart uses bars, so we can compare the counts quickly.
Key ideas
- Count each thing once, and record it.
- Tally marks come in groups of five.
- A table lists the results in rows, with a heading.
- In a pictogram, each picture stands for one thing.
- In a bar chart, the tallest bar is the most.
Method. Count the ant marks in groups of five first. Then count the marks left over.
- Count the full groups of five. Each full group has four upright marks and one line across them.1 group of five = 5 marks
- Count the marks left over. These are not in a full group.3 left over
- Add them together. 5 and 3 make 8.5 + 3 = 8
- Write the answer. 8
Check. Count every mark one at a time, and you also get 8. ✓
Watch out. Count the groups of five first. Then count the single marks that are left over.
Key: each picture stands for 1 thing.
Method. Find each count. Then take the smaller count away from the bigger count.
- Read the count for worms. There are 7.worms: 7
- Read the count for snails. There are 2.snails: 2
- Take the smaller count away from the bigger one. The difference is how many more.7 − 2 = 5
- Write the answer. 5
Check. Add the difference back on: 2 + 5 = 7. ✓
Watch out. Take the smaller number away from the bigger one, not the other way round.
Method. Compare the numbers. The smallest number is the fewest.
- Write down each number. Put each number next to its name.ants 6, worms 3, snails 5
- Find the smallest number. 3 is the smallest number.smallest: 3
- Write the answer. worms has 3.worms
Check. Every other number is bigger than 3. ✓
Watch out. Check every number, not only the first two.
Watch out
Watch out: count each thing once. Make the fifth mark a line across the other four.
Try it at home (with a grown-up). With a grown-up, sit by a window for 10 minutes. Count the birds you see in the garden, and make a tally chart. Then draw a bar chart of your counts. Which bird did you see the most?
Exam tip
Grown-up tip. Let your child make the tally marks and count them in fives. Ask: “Which one has the most? How many altogether?”
Exercise 1F Recording and reading tally charts, tables, pictograms and bar charts
Method. Count the sunny marks in groups of five first. Then count the marks left over.
- Count the full groups of five. Each full group has four upright marks and one line across them.no full group
- Count the marks left over. These are not in a full group.4 left over
- Add them together. 0 and 4 make 4.0 + 4 = 4
- Write the answer. 4
Check. Count every mark one at a time, and you also get 4. ✓
Watch out. Count the groups of five first. Then count the single marks that are left over.
Method. Count the cloudy marks in groups of five first. Then count the marks left over.
- Count the full groups of five. Each full group has four upright marks and one line across them.1 group of five = 5 marks
- Count the marks left over. These are not in a full group.1 left over
- Add them together. 5 and 1 make 6.5 + 1 = 6
- Write the answer. 6
Check. Count every mark one at a time, and you also get 6. ✓
Watch out. Count the groups of five first. Then count the single marks that are left over.
Method. Count the windy marks in groups of five first. Then count the marks left over.
- Count the full groups of five. Each full group has four upright marks and one line across them.no full group
- Count the marks left over. These are not in a full group.1 left over
- Add them together. 0 and 1 make 1.0 + 1 = 1
- Write the answer. 1
Check. Count every mark one at a time, and you also get 1. ✓
Watch out. Count the groups of five first. Then count the single marks that are left over.
| Garden visitor | Count |
|---|---|
| birds | 6 |
| bees | 9 |
| butterflies | 4 |
| snails | 3 |
Method. Find the row for bees. Then read the number in that row.
- Find the row for bees. Look for the name in the first column.bees
- Read the number in the same row. That number is how many there are.bees: 9
- Write the answer. 9
Check. Read the same row again. The number is still 9. ✓
Watch out. Read the number in the same row as the name. Do not read the row above or below.
| Garden visitor | Count |
|---|---|
| birds | 6 |
| bees | 9 |
| butterflies | 4 |
| snails | 3 |
Method. Compare the numbers. The biggest number is the most.
- Write down each number. Put each number next to its name.birds 6, bees 9, butterflies 4, snails 3
- Find the biggest number. 9 is the biggest number.biggest: 9
- Write the answer. bees has 9.bees
Check. Every other number is smaller than 9. ✓
Watch out. Check every number, not only the first two.
| Garden visitor | Count |
|---|---|
| birds | 6 |
| bees | 9 |
| butterflies | 4 |
| snails | 3 |
Method. Find each count, then add them all together.
- Write down each count. Each count is one row.birds 6, bees 9, butterflies 4, snails 3
- Add the counts together. Add them all, so none is missed.6 + 9 + 4 + 3 = 22
- Write the answer. 22
Check. Add them again, starting from the last count, and you get 22. ✓
Watch out. Make sure every row is in your total, and no row is counted twice.
Key: each picture stands for 1 thing.
Method. Count the snails once each. Touch each one as you count it.
- Count them one at a time. Say each number as you touch one.1 2 3
- Read the last number. The last number is how many there are.3
- Write the answer. 3
Check. Count them again from the other end. You get 3 again. ✓
Watch out. Move each one to one side as you count it, so you do not count it twice.
Key: each picture stands for 1 thing.
Method. Find each count. Then take the smaller count away from the bigger count.
- Read the count for bees. There are 9.bees: 9
- Read the count for snails. There are 3.snails: 3
- Take the smaller count away from the bigger one. The difference is how many more.9 − 3 = 6
- Write the answer. 6
Check. Add the difference back on: 3 + 6 = 9. ✓
Watch out. Take the smaller number away from the bigger one, not the other way round.
Method. Compare the numbers. The smallest number is the fewest.
- Write down each number. Put each number next to its name.sunny 4, cloudy 6, rainy 3, windy 1
- Find the smallest number. 1 is the smallest number.smallest: 1
- Write the answer. windy has 1.windy
Check. Every other number is bigger than 1. ✓
Watch out. Check every number, not only the first two.
Method. Find each count. Then take the smaller count away from the bigger count.
- Read the count for cloudy. There are 6.cloudy: 6
- Read the count for rainy. There are 3.rainy: 3
- Take the smaller count away from the bigger one. The difference is how many more.6 − 3 = 3
- Write the answer. 3
Check. Add the difference back on: 3 + 3 = 6. ✓
Watch out. Take the smaller number away from the bigger one, not the other way round.
Method. Add the numbers for each pair. Find the pair that makes the total.
- List the pairs and their totals. Add the numbers for each pair.sunny 4 + cloudy 6 = 10; sunny 4 + rainy 3 = 7; sunny 4 + windy 1 = 5; cloudy 6 + rainy 3 = 9; cloudy 6 + windy 1 = 7; rainy 3 + windy 1 = 4
- Find the pair that makes 10. Only sunny and cloudy make 10.10 = 10
- Write the answer. sunny and cloudy
Check. sunny and cloudy together make 10. No other pair makes 10. ✓
Watch out. Check every pair. Two numbers that are both bigger than the target cannot make it.
Method. Count both rows, then check the claim.
- Read the count for rainy. There are 3.rainy: 3
- Read the count for sunny. There are 4.sunny: 4
- Check the claim. The claim says there are more rainy than sunny. The counts are 3 and 4.No
Check. 3 and 4 are different, so the claim is not right. ✓
Watch out. Compare the two counts, not how big the pictures look.
Chapter summary
| Skill | Method |
|---|---|
| Ask a question | A science question is one we can find out. We can look, measure, test or use a book. |
| Observe closely | Look closely and describe what you see. Use a hand lens, a ruler and a timer. |
| Fair test | Change only one thing. Keep everything else the same. Count or measure, and repeat to check. |
| Classify | Sort things into groups by a rule. Check each thing against the rule, one at a time. |
| Suggest an idea | Notice something, suggest an idea from it, then test the idea before you decide. |
| Record data | Use tally marks in fives, a table, a pictogram or a bar chart. Count each thing once. |
Can you…?
- I can ask a question that I can find out the answer to
- I can say which way would help me find the answer: look, measure, test or book
- I can look closely and measure with a ruler and a timer
- I can set up a fair test in which only one thing changes
- I can sort things into groups using one rule or two rules
- I can suggest an idea from what I notice, and say how I could test it
- I can record counts in a tally chart, a table, a pictogram or a bar chart
Key terms
- question
- something we want to find out
- observe
- look closely and notice details
- hand lens
- a tool that makes small things look bigger
- centimetre (cm)
- a unit for measuring length
- fair test
- a test in which only one thing changes
- classify
- sort things into groups using a rule
- idea
- a suggested answer, based on what we notice
- data
- information we collect, such as counts
- tally chart
- a chart that counts with marks, in groups of five
- pictogram
- a chart that uses one picture for each thing
- bar chart
- a chart that uses bars to show counts
Exercise 1Z Check-up
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.How could you find out how long a worm is?
- Pick the way. A length needs a ruler, so we lay the worm along the ruler.Way: measure
- Write the answer. measure
Check. Lay the worm along the ruler from the 0 mark. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Think about which tool makes small things look bigger.
- Read the question. We want to see tiny parts.tiny parts
- Choose the tool. A hand lens makes small things look bigger.hand lens
- Write the answer. hand lens
Check. A ruler and a timer do not make small things bigger. ✓
Watch out. Look through the hand lens slowly.
Method. Put the 0 mark at one end of the object. Then read the mark at the other end.
- Put the 0 mark at the end of the stick. Starting at 0 makes the count start in the right place.stick starts at 0
- Read the mark at the other end. The number there is how long it is.It ends at 6
- Write the length, with the unit. We measure length in centimetres, written cm.6 cm
Check. Count along the ruler from 0 to 6, one centimetre at a time. ✓
Watch out. Start at 0, not at the end of the ruler. Otherwise the answer will be wrong.
Method. Read the start time and the stop time. Then count the minutes between them.
- Read the start time. The timer starts at this time.4:00
- Read the stop time. The timer stops at this time.4:06
- Count the minutes from start to stop. Count on one minute at a time.1 2 3 4 5 6
- Write the answer. 6
Check. Count back from the stop time to the start time. You get 6 minutes. ✓
Watch out. The minute hand goes all the way round the clock once in an hour. Count minutes, not hours.
Method. Compare the numbers. The smallest number is the fewest.
- Write down each number. Put each number next to its name.Jar X 6, Jar Y 10, Jar Z 8
- Find the smallest number. 6 is the smallest number.smallest: 6
- Write the answer. Jar X has 6.Jar X
Check. Every other number is bigger than 6. ✓
Watch out. Check every number, not only the first two.
Method. Check how many things change.
- Find the thing that changes. Only the jar changes.jar
- Check the other things. The cubes stay the same.cubes: same
- Write the answer. yes
Check. One thing changed, and the rest was kept the same. ✓
Watch out. A fair test changes only one thing.
Method. Think about which animal is covered in feathers.
- Check the cat and the dog. Both are covered in fur.fur
- Check the bird. A bird has feathers.bird: feathers
- Write the answer. bird
Check. Only one animal here has feathers. ✓
Watch out. Feathers are not fur.
Method. Count the worm marks in groups of five first. Then count the marks left over.
- Count the full groups of five. Each full group has four upright marks and one line across them.2 groups of five = 10 marks
- Count the marks left over. These are not in a full group.2 left over
- Add them together. 10 and 2 make 12.10 + 2 = 12
- Write the answer. 12
Check. Count every mark one at a time, and you also get 12. ✓
Watch out. Count the groups of five first. Then count the single marks that are left over.
| Bird | Count |
|---|---|
| robins | 3 |
| sparrows | 5 |
| blackbirds | 2 |
Method. Add the numbers for each pair. Find the pair that makes the total.
- List the pairs and their totals. Add the numbers for each pair.robins 3 + sparrows 5 = 8; robins 3 + blackbirds 2 = 5; sparrows 5 + blackbirds 2 = 7
- Find the pair that makes 8. Only robins and sparrows make 8.8 = 8
- Write the answer. robins and sparrows
Check. robins and sparrows together make 8. No other pair makes 8. ✓
Watch out. Check every pair. Two numbers that are both bigger than the target cannot make it.
Method. Think about which idea we can test by looking and counting.
- Read (a). We could watch the bird on a lawn and count the insects it picks up.a: can be tested
- Read (b). Most garden birds do not fly underwater, and we cannot test this safely.b: not a fair idea
- Write the answer. a
Check. Watch the bird for 5 minutes and count what it does. ✓
Watch out. A good idea gives a reason we can check.
Total 16 marks. Allow about 16 minutes.
Exercise 1X End-of-chapter quiz
Method. Count the cubes once each. Touch each one as you count it.
- Count them one at a time. Say each number as you touch one.1 2 3 4 5 6 7
- Read the last number. The last number is how many there are.7
- Write the answer. 7
Check. Count them again from the other end. You get 7 again. ✓
Watch out. Move each one to one side as you count it, so you do not count it twice.
Method. An observation is something we can see now.
- Read (a). We can see the colour of the shell.a: we can see it
- Read (b). We cannot see whether a snail is sleepy. That is a guess.b: a guess
- Write the answer. a
Check. Look at the shell, and you can see its colour. ✓
Watch out. An observation says what we can see now.
Method. Think about what the question asks us to find out. Then pick the way that finds the answer.
- Read the question. Think about what we need to find out.Whether worms like the dark?
- Pick the way. We can put worms in light and dark places and see where they go.Way: test
- Write the answer. test
Check. Use the same worms and the same time for each place. ✓
Watch out. Some questions can be answered in more than one way. Choose the one that fits best.
Method. Put the 0 mark at one end of the object. Then read the mark at the other end.
- Put the 0 mark at the end of the pencil. Starting at 0 makes the count start in the right place.pencil starts at 0
- Read the mark at the other end. The number there is how long it is.It ends at 8
- Write the length, with the unit. We measure length in centimetres, written cm.8 cm
Check. Count along the ruler from 0 to 8, one centimetre at a time. ✓
Watch out. Start at 0, not at the end of the ruler. Otherwise the answer will be wrong.
| Garden visitor | Count |
|---|---|
| birds | 6 |
| bees | 9 |
| butterflies | 4 |
| snails | 3 |
Method. Find each count. Then take the smaller count away from the bigger count.
- Read the count for birds. There are 6.birds: 6
- Read the count for snails. There are 3.snails: 3
- Take the smaller count away from the bigger one. The difference is how many more.6 − 3 = 3
- Write the answer. 3
Check. Add the difference back on: 3 + 3 = 6. ✓
Watch out. Take the smaller number away from the bigger one, not the other way round.
Method. Count the ant marks in groups of five first. Then count the marks left over.
- Count the full groups of five. Each full group has four upright marks and one line across them.2 groups of five = 10 marks
- Count the marks left over. These are not in a full group.3 left over
- Add them together. 10 and 3 make 13.10 + 3 = 13
- Write the answer. 13
Check. Count every mark one at a time, and you also get 13. ✓
Watch out. Count the groups of five first. Then count the single marks that are left over.
| Bird | Count |
|---|---|
| robins | 3 |
| sparrows | 5 |
| blackbirds | 2 |
Method. Add the numbers for each pair. Find the pair that makes the total.
- List the pairs and their totals. Add the numbers for each pair.robins 3 + sparrows 5 = 8; robins 3 + blackbirds 2 = 5; sparrows 5 + blackbirds 2 = 7
- Find the pair that makes 5. Only robins and blackbirds make 5.5 = 5
- Write the answer. robins and blackbirds
Check. robins and blackbirds together make 5. No other pair makes 5. ✓
Watch out. Check every pair. Two numbers that are both bigger than the target cannot make it.
Method. Find the test that compares light and dark places.
- Read choice a. It compares light and dark places, and watches the worms.a: compares
- Read choice b. Naming the worms does not test where they like to be.b: no test
- Write the answer. a
Check. Use the same kind of worm, and the same time, in each place. ✓
Watch out. A good test compares two things, and changes only one.
Method. Find each count. Then take the smaller count away from the bigger count.
- Read the count for cloudy. There are 6.cloudy: 6
- Read the count for sunny. There are 4.sunny: 4
- Take the smaller count away from the bigger one. The difference is how many more.6 − 4 = 2
- Write the answer. 2
Check. Add the difference back on: 4 + 2 = 6. ✓
Watch out. Take the smaller number away from the bigger one, not the other way round.
Method. Compare the numbers. The biggest number is the most.
- Write down each number. Put each number next to its name.Cup A 9, Cup B 12, Cup C 7
- Find the biggest number. 12 is the biggest number.biggest: 12
- Write the answer. Cup B has 12.Cup B
Check. Every other number is smaller than 12. ✓
Watch out. Check every number, not only the first two.