Bridge 100 by adding or subtracting a single-digit number | Maths

Starter quiz

What is the missing addend? 6 + ______ = 10
- '4' ✓
What is the most efficient way to partition 6 to complete the calculation 7 + 6?
- 3 and 3 ✓
- 4 and 2
- 5 and 1
What is 1 more than 99?
- '100' ✓
105 − ______ = 100
- '5' ✓
What number is shown by the arrow?
- 105
- 115
- 125 ✓
- 135
Match the base ten representations to the numbers.
- A
  
  ⇔
  
  111 ✓
- B
  
  ⇔
  
  110 ✓
- C
  
  ⇔
  
  101 ✓

What is the missing addend? 96 + ______ = 100
- '4' ✓
What's the most efficient way to partition 7 to complete 99 + 7 = 106?
- 1 and 6 ✓
- 2 and 5
- 3 and 4
What calculation is represented?
- 99 + 4 = 103
- 98 + 3 = 101
- 98 + 4 = 102 ✓
- 97 + 5 = 102
What addend is missing from the number line representation?
- '3' ✓
What is the missing number? 108 − ______ = 99
- '9' ✓
Match the equations to the answers.
- 101 − 5 =
  
  ⇔
  
  96 ✓
- 102 − 7 =
  
  ⇔
  
  95 ✓
- 99 + 6 =
  
  ⇔
  
  105 ✓
- 98 + 8 =
  
  ⇔
  
  106 ✓

Loading worksheet ...

Loading presentation ...

Knowledge of number facts to 20 can support calculation across the 100 boundary.
If 8 plus 7 is equal to 15 then 98 plus 7 is equal to 90 plus 15 which equals 105
Knowledge of place value can help when counting forwards across the 100 boundary.

Pupils may not partition numbers in efficient ways to add and subtract them.

Encourage pupils to add or subtract to make 100 (e.g. when calculating 103-7, subtract 3 to equal 100, then subtract 4 to equal 96).

Bridging - A strategy which uses addition or subtraction to cross a number boundary.
Partition - The act of splitting an object or value down into smaller parts.