Bringing two or more numbers or things together to make a new total.

Solve problems using knowledge of addition and subtraction of 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

Look at the bar model.  Which value represents the whole?

Look at the bar model. How is the missing number calculated?

Read the word problem. Jacob has 170 cm of ribbon. Andeep cuts 70 cm from the ribbon. Izzy cuts 50 cm from the ribbon. How is the missing part calculated?

Read the word problem. Andeep needs 150 grams of flour to bake a cake. There are 60 grams in one bag of flour and 80 grams in another bag. How much more flour does Andeep need? {{ }} grams.

Jacob used partition and bridge through 100 as his strategy to solve 150 p - 70 p. Order the steps using his strategy.

Izzy collected rainwater outside in a jug. In week 1, there was 60ml of rain. In week 2, there was 10ml more than in week 1. How much rainwater did Izzy collect? {{ }} ml.

140 - 60 = 80. Which number is the minuend in this equation?

140 - 60 = 80.  60 in this equation is the {{ }}.

Which is the best way to partition the subtrahend in this equation? 150 - 70 = 80

What number is missing from this calculation? 120 − 70 = 120 − 20 − {{ }}.

Which partitioned subtrahend will help you to bridge 100?

Starter Quiz