New
New
Year 3

Bridge 100 by adding or subtracting a single-digit number

I can bridge 100 by adding or subtracting a single-digit number.

New
New
Year 3

Bridge 100 by adding or subtracting a single-digit number

I can bridge 100 by adding or subtracting a single-digit number.

Share activities with pupils
Share function coming soon...

Lesson details

Key learning points

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

Common misconception

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).

Keywords

  • 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.

Pupils will need to have a good grasp of number pairs that total 10 to access the learning in this lesson. Base 10 blocks may be useful for this lesson, although pupils will need to use this flexibly alongside the images provided.
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).

Video

Loading...

6 Questions

Q1.
What is the missing addend? 6 + = 10
Correct Answer: 4, four
Q2.
What is the most efficient way to partition 6 to complete the calculation 7 + 6?
Correct answer: 3 and 3
4 and 2
5 and 1
Q3.
What is 1 more than 99?
Correct Answer: 100, one hundred
Q4.
105 − = 100
Correct Answer: 5, five
Q5.
What number is shown by the arrow?
An image in a quiz
105
115
Correct answer: 125
135
Q6.
Match the base ten representations to the numbers.
An image in a quiz
Correct Answer:A,111

111

Correct Answer:B,110

110

Correct Answer:C,101

101

6 Questions

Q1.
What is the missing addend? 96 + = 100
Correct Answer: 4, four
Q2.
What's the most efficient way to partition 7 to complete 99 + 7 = 106?
Correct answer: 1 and 6
2 and 5
3 and 4
Q3.
What calculation is represented?
An image in a quiz
99 + 4 = 103
98 + 3 = 101
Correct answer: 98 + 4 = 102
97 + 5 = 102
Q4.
What addend is missing from the number line representation?
An image in a quiz
Correct Answer: 3, three
Q5.
What is the missing number? 108 − = 99
Correct Answer: 9, nine
Q6.
Match the equations to the answers.
Correct Answer:101 − 5 =,96

96

Correct Answer:102 − 7 = ,96

96

Correct Answer:99 + 6 = ,105

105

Correct Answer:98 + 8 = ,106

106