Bridge 100 by adding or subtracting a single-digit number
Lesson details
Learning outcome
I can bridge 100 by adding or subtracting a single-digit number.
Key learning points
- 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.
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.
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).
Teacher tip
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.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is the missing addend? 6 + = 10
Q2.What is the most efficient way to partition 6 to complete the calculation 7 + 6?
Q3.What is 1 more than 99?
Q4.105 − = 100
Q5.What number is shown by the arrow?
Q6.Match the base ten representations to the numbers.
111
110
101
Assessment exit quiz
6 Questions
Q1.What is the missing addend? 96 + = 100
Q2.What's the most efficient way to partition 7 to complete 99 + 7 = 106?
Q3.What calculation is represented?
Q4.What addend is missing from the number line representation?
Q5.What is the missing number? 108 − = 99
Q6.Match the equations to the answers.
96
95
105
106
To help you plan your 3 maths lesson on: Bridge 100 by adding or subtracting a single-digit number, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 3 maths lesson on: Bridge 100 by adding or subtracting a single-digit number, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 2 maths lessons from the Bridging 100: counting on and back in 10s, adding/subtracting multiples of 10 unit, dive into the full primary maths curriculum, or learn more about lesson planning.