74 + 3: just add the ones, 4 + 3 = 7, so 77.
Addition to 100
Adding to 100 practice, from 87 + 4 to 34 + 46 = 80: a single digit first, then two 2-digit numbers with and without crossing ten, and number bonds to 100.
Your child can start here once they can add and subtract within 50 and find their way on the number line. Everything practised separately comes together here: in 58 + 37 a child handles the tens, the ones and a new ten at once, and there is no room left for a step that still wobbles.
Usually taught in Year 2–3 in England and Wales, around ages 6 to 8. Every child goes at their own pace; this is a guide, not a requirement.
The first of 26 exercises in this topic. See them all
What it looks like for your child
With one exercise from this topic as the example: Plus a single digit, crossing ten.
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2
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How it fits together
The arrows point to what can be done next. Whatever sits inside a box belongs to it.
Addition
Addition to 100
Two numbers to 100
+3 more
More numbers and balance to 100
All together
Can come next
first this, then that belongs to
Two numbers to 100
Choose two numbers that make the total together
Tens with tens, ones with ones: 32 + 45 = 70 + 7 = 77.
Jump to the next ten first: 68 + 5 = 68 + 2 + 3 = 73.
Turn it round: ? + 3 = 77 is the same as 77 − 3.
Tens first, then the ones: 47 + 35 = 77 + 5 = 82.
Turn it round: ? + 45 = 77 is the same as 77 − 45.
Turn it round: ? + 5 = 73 is the same as 73 − 5.
Jump to the next ten first: ? + 49 = 100 — from 49 to 50 is 1, then 50 more, so 51.
Look first: do the ones add up past ten?
Turn it round: ? + 35 = 82 is the same as 82 − 35.
More numbers and balance to 100
Look for numbers that make a round number together first, like 7 + 3.
Work out one side, then make the other side the same.
Work out what is already there first, then see how much is missing.
A race against time, for children who can already do it and want to be faster.
Look for numbers that make a round number together first, like 7 + 3.
Against the clock: how many can your child do in sixty seconds?
Work out what is already there first, then see how much is missing.
Mixed to 100
The same sum as 47 + 35 = 82, but ten times bigger: 470 + 350 = 820.
A race against time, for children who can already do it and want to be faster.
The same sum as 47 + 35 = 82, but a hundred times bigger: 4700 + 3500 = 8200.
Just like 45 + 55 = 100, but ten times bigger: 450 + 550 = 1000.
The same sum as 47 + 35 = 82, but a thousand times bigger: 47000 + 35000 = 82000.
Just like 45 + 55 = 100, but a hundred times bigger: 4500 + 5500 = 10000.
Just like 45 + 55 = 100, but a thousand times bigger: 45000 + 55000 = 100000.
All together
A long round of 60 mixed sums to finish.
- Plus and minus — on the Subtraction to 100 page
- Plus and minus: fill in — on the Subtraction to 100 page
- Quick: plus and minus — on the Subtraction to 100 page
- Plus and minus: three numbers — on the Subtraction to 100 page
- Plus and minus: balance — on the Subtraction to 100 page
- Plus and minus: big round — on the Subtraction to 100 page
Why it matters
To 100, everything practised separately in the earlier steps comes together. Your child adds two 2-digit numbers, with and without crossing a ten, and chooses which approach is handiest. Adding to 100 in their head is a skill that, once learnt, stays for good.
This step is also about seeing the bigger picture. A child who sees straight away that 58 + 37 will land somewhere between 90 and 100 makes fewer mistakes than one who only follows a recipe. The sums with hundreds and thousands build on that sense of size, up to a hundred thousand.
How to approach it
There are two good routes, and your child can choose. The first counts on in parts: start with the first number and add the tens first, then the ones, as in 36 + 28 → 56 → 64. The second rounds: 36 + 30 = 66, and because that was 2 too many, it becomes 64. Ask your child to do a sum both ways and tell you which felt nicer.
For ‘Make 100’, the secret is number bonds to 100: 64 and 36, 25 and 75, 81 and 19. A game works well here. You say a number, your child says the number that makes it up to 100, and then you swap. After a few days it gets surprisingly quick.
When is it secure?
All 10 right in one round, and no more than 25 seconds altogether. Around 2.5 seconds a sum shows your child is no longer counting.