Page 1 · Introduction
Adding and taking away, the smart way
Adding and subtracting are the building blocks of maths. There are clever little tricks that make them quick and easy to do in your head — and they help you get answers faster on the OC test.
The big ideaYou don’t always have to count one by one. Make numbers friendly (round to a ten), use doubles you already know, and count on from the bigger number.
💡We start with small, friendly numbers and build up gently. Take your time and try each trick.
On the real testWhere this appearsQuick adding and subtracting help all through the Mathematical Reasoning part of the OC test (sat in Year 4). Being fast leaves more time for the tricky questions.
Page 2 · Counting on
Start from the bigger number
When you add, start with the bigger number and count on. It’s faster than starting from the smaller one.
Work out: 3 + 8
Start from 8 (the bigger one) and count on 3: 9, 10, 11.
11
Work out: 2 + 9
Start from 9, count on 2: 10, 11.
11
Page 3 · Friendly tens
Make a ten
Numbers that add to 10 are friendly — they’re easy. Look for a ten hiding inside a sum.
Work out: 7 + 5
Take 3 from the 5 to make 7 into 10, then add the 2 left: 10 + 2 = 12.
12
Work out: 8 + 6
Take 2 from the 6 to make 10, add the 4 left: 10 + 4 = 14.
14
Page 4 · Near doubles
Use doubles you know
If you know a double like 6 + 6 = 12, you can work out 6 + 7 easily: it’s just one more.
Work out: 6 + 7
6 + 6 = 12, and 7 is one more, so 12 + 1 = 13.
13
Work out: 5 + 6
5 + 5 = 10, one more makes 11.
11
Page 5 · Taking away
Count back or count up
To subtract, you can count back — or, for numbers close together, count up from the smaller to the bigger.
Work out: 12 − 3
Count back 3 from 12: 11, 10, 9.
9
Work out: 11 − 9
Count up from 9 to 11: that’s 2 steps.
2
Level 1 · Easy
Warm up
Simple adding. Tap to check.
1. Work out: 4 + 5
4 + 5 = 9.
2. Work out: 6 + 3
6 + 3 = 9.
3. Work out: 7 + 2
7 + 2 = 9.
Level 2 · Medium
Building up
Making tens and near doubles.
1. Work out: 8 + 5
8 + 2 = 10, plus 3 left = 13.
2. Work out: 7 + 7
Double 7 is 14.
3. Work out: 6 + 8
8 + 2 = 10, plus 4 left = 14.
Level 3 · Hard
Getting tougher
Taking away.
1. Work out: 14 − 6
Count back 6 from 14: 8.
2. Work out: 13 − 5
13 − 5 = 8.
3. Work out: 15 − 9
Count up from 9 to 15: 6 steps.
Level 4 · Challenge
Challenge
Bigger numbers and two steps.
1. Work out: 23 + 9
23 + 10 = 33, take 1 back = 32.
2. Work out: 30 − 12
30 − 12 = 18.
3. Sam has 25 cards and gets 8 more, then gives away 5. How many now?
25 + 8 = 33, then 33 − 5 = 28.
Page 10 · Well done
You’ve finished Addition & Subtraction
You can now add and subtract using clever tricks — counting on, making tens, near doubles, and counting back or up. These make maths quicker and easier every day.
RememberStart from the bigger number, look for a friendly ten, use doubles you know, and count back or up when taking away.
🎉Great work! Try another module next — every one helps you get ready.
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