Year 1: Comparing and ordering numbers to 20
Part of the Year 1 numbers to 20 chapter. Chapter overview · whole chapter on one page · Download worksheet (PDF) · Answers (PDF)
Comparing and ordering numbers to 20
On a number line, the bigger number is further to the right. The smaller number is further to the left.
A number from eleven to twenty is always bigger than any number from one to nine. Fifteen is ten and five more, so it is bigger than nine.
We can put numbers in order, smallest first or biggest first. The number between two numbers sits in the middle of them.
Key ideas
- Bigger numbers are further to the right.
- Any number from 11 to 20 is bigger than any number from 1 to 9.
- Order means smallest first, or biggest first.
- The number between two numbers is in the middle of them.
Method. The biggest number is the one furthest to the right on the number line.
- Find each number on the number line. Look at where each one sits.
- Find the biggest number. Bigger numbers are further right.14 is the biggest number.
- Write the answer. 14
Check. Compare 14 with each of the others: 14 > each one. ✓
Watch out. Do not look at the size of the writing. Compare the numbers.
Key words. Smallest is the least. Biggest is the most.
Method. Smallest first. Look at where each number sits on the number line.
- Find each number on the number line. Numbers further to the left are smaller.
- Put the numbers in order. Start with the smallest and go to the next one.11, 12, 15, 18
- Write the numbers. 11, 12, 15, 18
Check. There are 4 numbers in the question and 4 in the answer. ✓
Watch out. Check you have not left a number out.
Key words. Between means in the middle of two numbers.
Method. The number between 16 and 18 sits in the middle of them.
- Find 16 and 18 on the number line. Put your finger on each one.
- Count on one from the smaller number. The number in the middle is one more than the smaller one.16 + 1 = 17
- Write the answer. 17
Check. Count on from 17 to 18: 17 + 1 = 18. ✓
Watch out. The number between is not one of the two numbers you started with.
Watch out
Watch out: 12 has two digits and 9 has one digit, and 12 is the bigger number. Do not guess from the digits. Look at the number line.
Exam tip
Grown-up tip. Write five numbers from 1 to 20 on cards and mix them up. Ask your child to put them in order, smallest first. Then ask: “Which number is between 13 and 15?”
Exercise 4E Comparing, ordering and between
Non-calculatorMethod. The biggest number is the one furthest to the right on the number line.
- Find each number on the number line. Look at where each one sits.
- Find the biggest number. Bigger numbers are further right.19 is the biggest number.
- Write the answer. 19
Check. Compare 19 with each of the others: 19 > each one. ✓
Watch out. Do not look at the size of the writing. Compare the numbers.
Method. The smallest number is the one furthest to the left on the number line.
- Find each number on the number line. Look at where each one sits.
- Find the smallest number. Smaller numbers are further left.16 is the smallest number.
- Write the answer. 16
Check. Compare 16 with each of the others: 16 < each one. ✓
Watch out. Do not look at the size of the writing. Compare the numbers.
Method. The biggest number is the one furthest to the right on the number line.
- Find each number on the number line. Look at where each one sits.
- Find the biggest number. Bigger numbers are further right.12 is the biggest number.
- Write the answer. 12
Check. Compare 12 with each of the others: 12 > each one. ✓
Watch out. Do not look at the size of the writing. Compare the numbers.
Key words. Smallest is the least. Biggest is the most.
Method. Smallest first. Look at where each number sits on the number line.
- Find each number on the number line. Numbers further to the left are smaller.
- Put the numbers in order. Start with the smallest and go to the next one.11, 14, 17
- Write the numbers. 11, 14, 17
Check. There are 3 numbers in the question and 3 in the answer. ✓
Watch out. Check you have not left a number out.
Key words. Smallest is the least. Biggest is the most.
Method. Biggest first. Look at where each number sits on the number line.
- Find each number on the number line. Numbers further to the left are smaller.
- Put the numbers in order. Start with the biggest and go to the next one.20, 13, 9
- Write the numbers. 20, 13, 9
Check. There are 3 numbers in the question and 3 in the answer. ✓
Watch out. Check you have not left a number out.
Key words. Between means in the middle of two numbers.
Method. The number between 12 and 14 sits in the middle of them.
- Find 12 and 14 on the number line. Put your finger on each one.
- Count on one from the smaller number. The number in the middle is one more than the smaller one.12 + 1 = 13
- Write the answer. 13
Check. Count on from 13 to 14: 13 + 1 = 14. ✓
Watch out. The number between is not one of the two numbers you started with.
Key words. Between means in the middle of two numbers.
Method. The number between 18 and 20 sits in the middle of them.
- Find 18 and 20 on the number line. Put your finger on each one.
- Count on one from the smaller number. The number in the middle is one more than the smaller one.18 + 1 = 19
- Write the answer. 19
Check. Count on from 19 to 20: 19 + 1 = 20. ✓
Watch out. The number between is not one of the two numbers you started with.
Key words. More means a bigger number. Fewer means a smaller number. The same means equal.
Method. Count each group, then see which number is bigger.
- Count group A. Touch each one once.Group A: 14 apples
- Count group B. Touch each one once.Group B: 11 stars
- Compare the two numbers. The bigger number has more. The smaller number has fewer.14 > 11
- Write the answer. Group A has more apples.
Check. Match one to one: each thing in one group gets a partner from the other. The group with a thing left over has more. ✓
Watch out. Groups can look bigger when the things are spread out. Always count them.
Key words. More means a bigger number. Fewer means a smaller number. The same means equal.
Method. Count each group, then see which number is smaller.
- Count group A. Touch each one once.Group A: 16 cubes
- Count group B. Touch each one once.Group B: 19 balls
- Compare the two numbers. The bigger number has more. The smaller number has fewer.16 < 19
- Write the answer. Group A has fewer cubes.
Check. Match one to one: each thing in one group gets a partner from the other. The group with a thing left over has more. ✓
Watch out. Groups can look bigger when the things are spread out. Always count them.
Method. Count each person’s things, then compare the two numbers.
- Count what Sam has. Touch each one once.Sam: 13
- Count what Priya has. Touch each one once.Priya: 18
- Compare the two numbers. The bigger number is more.18 is bigger than 13
- Write the answer. Priya has more.
Check. The bigger number is further to the right on the number line. ✓
Watch out. Compare the numbers, not the names.
Key words. Smallest is the least. Biggest is the most.
Method. Smallest first. Look at where each number sits on the number line.
- Find each number on the number line. Numbers further to the left are smaller.
- Put the numbers in order. Start with the smallest and go to the next one.5, 10, 15, 20
- Write the numbers. 5, 10, 15, 20
Check. There are 4 numbers in the question and 4 in the answer. ✓
Watch out. Check you have not left a number out.
Key words. Between means in the middle of two numbers.
Method. The number between 14 and 16 sits in the middle of them.
- Find 14 and 16 on the number line. Put your finger on each one.
- Count on one from the smaller number. The number in the middle is one more than the smaller one.14 + 1 = 15
- Write the answer. 15
Check. Count on from 15 to 16: 15 + 1 = 16. ✓
Watch out. The number between is not one of the two numbers you started with.
Method. Compare 9 and 15 on the number line. The number further to the right is bigger.
- Find 9 and 15 on the number line. Look at where each one sits.9 and 15
- Compare the two numbers. 15 is ten and five more. That is more than 9.15 is bigger than 9
- Write the answer. No. 15 is bigger than 9, because 15 is 10 and 5 more.
Check. Count on from 9 to 15. You pass the 10. ✓
Watch out. A short word does not mean a small number. Compare the numbers.
Key words. Smallest is the least. Biggest is the most.
Method. Biggest first. Look at where each number sits on the number line.
- Find each number on the number line. Numbers further to the left are smaller.
- Put the numbers in order. Start with the biggest and go to the next one.19, 13, 11
- Write the numbers. 19, 13, 11
Check. There are 3 numbers in the question and 3 in the answer. ✓
Watch out. Check you have not left a number out.