An addend means any of the numbers that are added together.

Bridging 100 means partitioning one addend to make a number bond to 100 then adding the remaining part.

Bridge 100 by adding in multiples of 10

Maths

In this unit pupils will use known facts to find multiples of ten that compose 100  and use known facts to find complements to 100.  In the future unit pupils will find a 2-digit number and a 1 or 2-digit number that compose 100. Pupils will position 3-digit numbers on a number line and estimate the position of 3-digit numbers on unmarked number lines. They will compare and order 3 digit numbers.

In the prior unit pupils reviewed and secured previous knowledge of add 3 addends, understanding they can be added in any order, bridging through 10. In this unit pupils will use known facts to find multiples of ten that compose 100  and use known facts to find complements to 100.

Securing place value to 100 and applying to addition and subtraction

What are the addends in this calculation 90 + 30 = 120 ?

If I know 6 + 5 = 11 what is 6 tens + 5 tens? {{ }}

When adding 80 to 60, how can the addend 60 be partitioned to bridge 100?

Which addition is equivalent to 80 + 20 + 50?

 A number has been partitioned into something and 40 to bridge 100. What is the missing addend?  70 + {{ }} + 50 = 150

What is the missing part on the bar model?

What is the missing whole on the bar model?

Use this bar model. Which addition calculations are correct?

 170 = 40 + 100 + {{ }}.  What is the missing part?

Sofia buys some ribbon that is 170 cm long. She gives 70 cm to her friend. How much does she have left ? {{ }} cm.

Which calculations could represent this bar model? 

This lesson will soon be taken down.

Bridge 100 by adding in multiples of 10

Lesson outcome