Add 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

Which representation shows that the ‘bridge 10’ strategy has been used to solve 7 + 5 = 12?    

How would 6 be partitioned to ‘bridge 10’ in this equation?  8 + 6 = 14

How can we solve this equation? 16 + 7 = ___  

Look at the number line. What is the missing multiple of 10?  

What is the missing addend on this number line?

Alex represents the equation 32 + 8 = ___    Which known fact could he use to solve it more efficiently? 

Use the picture to complete the stem sentence. We know that 7 plus 3 is equal to 10, so we also know that {{ }} plus 3 is equal to 30  

Which of the following numbers will complete the equation? 65 + 5 = ___

Which equation would be next in this pattern? 10 − 8 = 2,  20 − 8 = 12, 30 − 8 = 22 ...

What is the missing addend in the next equation? Remember, you can partition the two-digit number to help you see the ones more clearly.  52 + 8 = 60, 53 + 7 = 60, 54 + {{ }} = 60 ... 

I know that 10 − 1 = 9, so I also know that 30 − 1 = {{ }}

This lesson will soon be taken down.

Add by bridging a multiple of ten

Lesson outcome