Year 6 Arithmetic (SATs): Negative numbers in context
Part of the Year 6 Arithmetic (SATs) place value and the four operations chapter. Chapter overview · whole chapter on one page
Negative numbers in context
Rule
A negative number is less than zero. On a number line, -1 is one step below 0 and -5 is five steps below.
Counting up moves towards zero and then into the positives. Counting down moves further below zero.
The bigger the negative number ignoring its minus sign, the smaller the number: -9 is less than -2.
Key ideas
- Negative numbers are below zero: -1, -2, -3 ...
- Going up from -4 by 3 gives -1: the count stops at -1, not at 1.
- Less than means further left on the number line.
- Counting up from a negative number moves towards zero.
Method. Count up 3 steps from -4 on a number line.
- Start at -4. The thermometer starts at -4°C.-4°C
- Count up 3 steps. Each step adds 1: -3, -2, -1.-4 → -3 → -2 → -1
- Read the answer. Three steps up from -4 is -1.-4 + 3 = -1
- Write the answer. -1°C
Check. -1 + 1 = 0, so -1 is one step below zero. ✓
Watch out. Do not go up past zero: -4 + 3 is -1, not 1.
Method. Move up 9 metres from -12 by counting up through the negatives.
- Start at -12. The diver is 12 m below the surface.-12 m
- Count up 9 metres. Going up adds to the number: -12 + 9 = -3.-12 + 9 = -3
- Read the answer in the context. She is 3 m below the surface.-3 m
- Write the answer. -3 m
Check. She is still below the surface, so the answer is negative. ✓
Method. The further a negative number is from zero, the colder it is.
- Compare the two temperatures. Both are below zero.-9 and -2
- Think about the number line. -9 is further left than -2, so it is less.-9 < -2
- Say which is colder. The smaller temperature is colder.-9°C is colder
- Write the answer. -9°C
Check. -9 is less than -2. ✓
Watch out. -9 is less than -2, even though 9 is bigger than 2.
Exercise 1B Practice: negative numbers in context
Non-calculatorMethod. Count up 2 from -5.
- Count up 2 steps. -5 → -4 → -3.-5 + 2 = -3
- Write the answer. -3
Check. Count back 2 from -3 to check you reach -5. ✓
Method. Count each step from -3 to 2.
- List the steps. Go through zero: -3, -2, -1, 0, 1, 2.-3 → -2 → -1 → 0 → 1 → 2
- Count the steps. There are five steps between the numbers.5 steps
- Write the answer. 5
Check. Count the numbers in the list: 6 numbers, 5 gaps. ✓
Watch out. Count the gaps between the numbers, not the numbers themselves.
Method. Test each choice against the question.
- Read what the question asks. Decide what you need to find or check.
- Test the choice. -7 is the furthest below zero, so it is the least.-7°C is right
- Reject the other choices. -2 is warmer. 0 and 3 are not below zero.-2°C and 0°C and 3°C are not right
- Write the answer. -7°C
Check. -7°C is right. ✓
Method. Count up 6 from -6.
- Count up 6 steps. -6 → -5 → -4 → -3 → -2 → -1 → 0.-6 + 6 = 0
- Read the answer. The temperature reaches zero.0°C
- Write the answer. 0°C
Check. Six steps up from -6 lands on 0. ✓
Method. Count down 4 from 1.
- Count down 4 steps. 1 → 0 → -1 → -2 → -3.1 - 4 = -3
- Write the answer. -3
Check. Count up 4 from -3 to get back to 1. ✓
Method. Count down 4 from 1, through zero.
- Count down 4 steps. 1 → 0 → -1 → -2 → -3.1 - 4 = -3
- Read the answer. The temperature is 3 degrees below zero.-3°C
- Write the answer. -3°C
Check. Counting up 4 from -3 returns to 1. ✓
Method. Add the payment to the balance.
- Start at -£35. The account is £35 overdrawn.-£35
- Add £60. Adding 60 to -35 gives 25.-35 + 60 = 25
- Write the answer. £25
Check. The new balance is £25 in credit. ✓
Method. Count up 9 from -12.
- Count up 9 steps. -12 → -3 is 9 steps up.-12 + 9 = -3
- Read the answer. He is 3 m below the surface.-3 m
- Write the answer. -3 m
Check. Check: -3 - 9 = -12. ✓
Method. Count the steps from 3 down to -5 through zero.
- Count down to zero. From 3 to 0 is 3 degrees.3 degrees
- Count from zero to -5. From 0 to -5 is 5 degrees.3 + 5 = 8 degrees
- Write the answer. 8
Check. Check: 3 - (-5) = 3 + 5 = 8. ✓
Watch out. Count through zero: the fall is not 3 minus 5.
Method. Count up 5 from -2.
- Count up 5 floors. From -2 up to 0 is 2 floors; 3 more floors reach 3.-2 + 5 = 3
- Write the answer. 3
Check. Count up 2 to reach 0, then 3 more to reach 3. ✓
Method. Test each choice against the question.
- Read what the question asks. Decide what you need to find or check.
- Test the choice. -9 is closer to zero, so it is greater.-9 is right
- Reject the other choices. -15 is further below zero, so it is less.-15 are not right
- Write the answer. -9
Check. -9 is right. ✓
Method. Look at the number line.
- Place both numbers. -2 is nearer zero than -7.-2 and -7
- Compare. Numbers nearer zero, on the right of the number line, are greater.-2 > -7
- Write the answer. No, -2 is bigger because it is closer to zero.
Check. Counting from -7 to -2 goes up 5. ✓