Cross the hundreds boundary when adding and subtracting any 2-digit multiple of 10 | Maths

Starter quiz

Which number pairs have a total of 10?
- 7 + 3 ✓
- 2 + 8 ✓
- 5 + 4
- 0 + 9
What is 40 + 10?
- '50' ✓
What is 20 + 20?
- '40' ✓
What is 10 less than 103?
- 83
- 93 ✓
- 97
- 113
Match up the equations to the answers.
- 125 − 10 =
  
  ⇔
  
  115 ✓
- 115 + 10 =
  
  ⇔
  
  125 ✓
- 115 − 10 =
  
  ⇔
  
  105 ✓
- 125 + 10 =
  
  ⇔
  
  135 ✓
Ping has a mass of 94 kg. Polly is 10 kg heavier. What is Polly's mass in kg?
- '104' ✓

Which numbers are multiples of 10?
- 65
- 60 ✓
- 106
- 140 ✓
Which calculations cross the 100s boundary?
- 87 + 10
- 101 − 10 ✓
- 89 + 20 ✓
- 112 − 10
What is 90 + 20?
- '110' ✓
What is 116 − 10?
- 96
- 106 ✓
- 115
- 126
Penny is 95 cm tall. She puts on a green hat which is 30 cm tall. What is the total height of Penny and her hat?
- 65 cm
- 105 cm
- 115 cm
- 125 cm ✓
Piper and her blue hat have a total height of 107 cm. If her hat is 40 cm tall, how tall is Piper in cm?
- '67' ✓

Loading worksheet ...

Loading presentation ...

When you add and subtract multiples of 10, the ones digit stays the same.
When you add and subtract multiples of 10, the tens digit and sometimes the 100s digit will change.
Number facts can help when adding and subtracting multiples of 10

Pupils may have difficultly partitioning 10s when crossing the 100s boundary. (e.g. 125 - 40)

Pupils practice adding to/subtracting from multiples of 10 (e.g. 130 - 50) before exploring non-multiples of 10 (e.g. 85 + 30)

Multiple - The result of multiplying a number by another whole number.
100s boundary - The point at which the numbers change into 100s numbers, or from one set of hundreds to another.