New
New
Year 5

# Use knowledge of positive and negative numbers to calculate intervals

I can use knowledge of positive and negative numbers to calculate intervals.

New
New
Year 5

# Use knowledge of positive and negative numbers to calculate intervals

I can use knowledge of positive and negative numbers to calculate intervals.

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## Lesson details

### Key learning points

1. Differences between values are always positive
2. Calculating differences across zero is the same as bridging through zero

### Common misconception

Pupils sometimes answer a question like ‘What is the difference between −5℃ and 3℃?’ with ‘−8℃’.

Remind pupils that these differences are always positive by asking them to count forwards from the lower value to the higher value.

### Keywords

• Bridging - A strategy which uses addition or subtraction to cross a number boundary.

• Partitioning - Splitting a number or object into smaller parts.

Generalisations within this lesson about negative numbers should be regularly reinforced. Using choral repetition or fill in the gaps are great strategies for this.
Teacher tip

### Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

## Starter quiz

### 6 Questions

Q1.
Tick all of the options that show 17 partitioned into two parts.
13 and 5
8 and 7
Q2.
Order these temperatures from warmest to coldest.
1 - 20℃
2 - 0℃
3 - −1℃
4 - −10℃
5 - −40℃
Q3.
Tick all the statements that are true.
The temperature was −7℃. One hour later it was −5℃. It got colder.
Correct answer: −3℃ is warmer than −4℃.
−5℃ is colder than −7℃.
Correct answer: These temperatures are getting warmer as they go along: −7℃, −6℃, −4℃, −2℃
Q4.
Put the following numbers into descending order.
1 - 0.1
2 - 0
3 - −0.01
4 - −16.5
5 - −17
Q5.
38 + 49 =
Q6.
Tick all the temperatures that would appear in between −30℃ and −20℃ on a number line.
−31℃
−19℃
−40℃

## Exit quiz

### 6 Questions

Q1.
The temperature was 5℃ in the day. Then it dropped to −4℃ at night. What was the change in temperature?
Correct Answer: 9, 9.0, Nine, nine
Q2.
Izzy was on the −3rd floor of a hotel. She took the lift to the 4th floor. How many floors did she go up?
Q3.
A lift in a hotel goes up six floors from the floor marked −2. What floor is it now on?
−8
−4
8
Q4.
The temperature is −7℃. Calculate the new temperature if it drops by 6℃.
Correct Answer: −13, - 13, minus 13, minus thirteen, negative thirteen
Q5.
There is a temperature increase of 5℃ from −11℃. What is the new temperature?
Correct Answer: -6, -6.0, - 6
Q6.
A submarine is below the surface of the water at −20 m. It goes up 5 m, then down 25 m. Where is it now?
0