# Jigsaw numbers; your secret weapon to teaching adding & subtracting

#### Embed key meths skills with your pupils & feel confident doing it

Are you teaching your KS1/KS2 students number bonds? We’ve got a teaching technique that will have you and your pupils adding and subtracting as quickly as the pros on Countdown! We’re not joking, they use a similar technique which we’ve adapted into Jigsaw Numbers for KS1/Ks2 learners. Once you’ve seen how it works, you won’t be able to unsee it.

### How do Jigsaw Numbers work?

If you think of a 2 piece jigsaw with a number on each piece, then Jigsaw Numbers are the total of the two numbers in the ‘finished picture’.

Jigsaw Numbers are special (10, 100, or 1000 for example). Explain the jigsaw analogy and ask children to complete the jigsaw, simple! For example, if 4 is one jigsaw piece, ask the child if they can tell us what would be on the missing piece if the total is 10. If we can *see* the maths it helps us to *understand* the maths.

### Try Jigsaw Numbers to 10

Ready for the challenge of Jigsaw numbers to 10? This is an oral activity to enjoy, have fun with it! Just ask your child to tell you the bottom number (when added to the top number equals 10), then refresh the screen. How fast can you go?

**Let’s put it into practice – How fast can you go?**

Simply refresh your screen (hit the F5 button) to change the number below!

2

?

### Try Jigsaw Numbers to 100

If your pupils are confident with Jigsaw Numbers to 10 then they’re ready for the challenge of Jigsaw numbers to 100.

This time, the bottom number added to the top number on the right equals 10. The bottom number added to the top number on the left equals 9. Two simple sums, which give you the jigsaw number to 100! In this example 2+8= 10 and 3+6= 9 so the answer is 68! Amazing! you just worked out 100 – 32 = 68 in seconds!

The target is still to find the missing jigsaw numbers quickly. Focus on the 2 simple sums, they always give you the right Jigsaw Number to 100!

**Let’s put it into practice – How fast can you go?**

Simply refresh your screen (hit the F5 button) to change the number below!

2 1

? ?

**Put their knowledge the the test**

When your pupils can answer both simple sums quickly, and you want to increase the challenge further, try reframing the questions;

- just ask the subtraction question (100 – 32 = ?) or,
- ask a missing number box questions (32 + = 100), or
- placing the questions into the context of money, or other units of measure (£1 – 32p = ?).

*Each of these questions uses 32 (from the first example provided above).*

### Discover more tools & techniques that will help you teach KS1/KS2 Maths with confidence

October can sometimes feel like a bit of a juggling act? You’ve just got to know your new class and are now under pressure to hit the ground running with the new curriculum as soon as possible. However, you’ll have some pupils who may have learning gaps from the previous year.

Big Maths is here to help you tackle this with **EASE** (**E**nsure **A**ll **S**teps are **E**asy!)

We’ll help you to identify pupils’ learning gaps (with no marking necessary) but also provide you with teacher-trusted guidance and resources to help bridge those gaps so no pupil gets left behind at the beginning of the new academic year.

# Get FREE access to interactive bite-size quizzes, learning gap insights and fun intervention resources

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