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## Interactive Bar   Holy Trinity C of E Primary School

Rooted in faith, we reach for the stars.

# w.c. 11.10.2021

We will be completing our Addition and Subtraction block this week.

## Monday - Round to estimate and approximate

We can use rounding and approximating to help us get more of an idea of whether our calculations are correct or not.  It is a useful tool!

For some of your calculations from the previous days, can you round your numbers to the nearest 1000 or 100 (as appropriate) then subtract them to see whether your answer was approximately the right size?

Try it for these additions too:

4367 + 8729 =

29371 + 459 =

6710 - 197 =

## Tuesday - Inverse operations (addition and subtraction)

We can use the inverse operation to check our calculations.

Use a dice or choose some numbers to create an addition involving two 4-digit numbers.  Carry out the addition then do the related subtraction to check that your working is correct.

Repeat for a subtraction, using the related addition to check your working.

Try the problem solving below for some extra challenges.

## Wednesday - Multi-step addition and subtraction problems

Once you have solved the problems from the video, can you create some two-step problems (involving addition and subtraction) of your own?

Remember to use the correct vocabulary for addition (total, altogether etc.) and subtraction (difference, more than, less than, fewer).

Thursday - solving balancing problems with addition and subtraction

The game below recaps what we mean by balancing problems, making sure we calculate the total on each side of the symbol.

Can you create some balancing equations where both sides give the same total?

Now, have a look at the PPT.  If you don't use it in slide show mode, you can move the place value discs to help you calculate the missing numbers (or it shows you how to use column addition and subtraction to do this).

Can you solve these balancing problems?

Friday

Today, we will recap and assess our learning from the addition and subtraction block.  Please look back through the videos on the following pages to recap the learning.