A strategy that involves using a multiple of ten as a 'bridge' so numbers can be partitioned to make use of bonds to ten and calculate efficiently.

Subtract by bridging a multiple of ten

Maths

In this unit pupils will add and subtract 1s and 10s from 2 digit numbers. They will use number facts to add/subtract a single-digit number to/from a 2-digit number. They will use a part-part-whole model to represent addition and subtraction. In the future unit pupils will learn to find 10 more or less than a 2-digit number They will  add and subtract 10 to/from a 2-digit number using number facts

In the prior unit pupils added 3 addends. They used strategies such as finding 2 addends to total 10 or 2 numbers to bridge though 10. In this unit pupils will add and subtract 1s and 10s from 2 digit numbers. They will use number facts to add/subtract a single-digit number to/from a 2-digit number. They will use a part-part-whole model to represent addition and subtraction.

Adding and subtracting ones and tens to and from 2-digit numbers

Look at the ten frames. Which equation does this image represent by showing ‘bridging 10’ to subtract?  

Look at the number line. How should 8 be partitioned to ‘bridge 10’ when subtracting here?  

How could we solve this equation? 24 − 5 = ___ 

Which number is missing on this number line representation?

Look at the number line. What is the missing multiple of ten?  

How would 5 be partitioned to ‘bridge 10’ in this equation?   8 + 5 = 13   

How can we solve this equation? 18 + 8 = ?  

What is the missing multiple of 10 on this number line? 

‘Bridge 10’ to find the missing sum in this equation. 27 + 6 = {{ }}  

38 + {{ }} = 43    What is the missing addend?

This lesson will soon be taken down.

Subtract by bridging a multiple of ten

Lesson outcome