Ink-saving
White cards with coloured borders and the animals in colour. For every animal rescued, your child colours in a star.
Download PDFAddition and subtraction to 20
Adding and subtracting within 20 comes later in Year 1 / Grade 1, with the big step across 10. This free worksheet practises both with 32 problems, with and without bridging through 10, for example 13 + 4 and 8 + 6, 17 − 5 and 15 − 7. Eight animals are stuck in the vines, and every right answer helps to set them free. Print it as a PDF, no sign-up needed.
Colouring version
Black and white for any printer. Once an animal is rescued, your child gets to colour it in.
Download PDFFree for home and the classroom. Licence: CC BY-NC 4.0, so feel free to print, copy and pass it on, just don't sell it. If you share the sheet online, please link to this page. CC BY-NC 4.0
How the worksheet works
- Each of the eight animals has three problems to work out and one gate problem, just like in the game: out of three answers, your child circles the right one.
- When all four problems are right, the animal is rescued: in the ink-saving version your child colours in its star, in the colouring version the whole animal.
- There is no answer key on purpose: check the answers together, or let your child check with the inverse calculation (8 − 3 = 5, so 5 + 3 = 8).
Tricks for adding and subtracting to 20
Bridge through 10
8 + 6 = 8 + 2 + 4 = 14First make 10, then add the rest. That is the heart of bridging through 10.
Back to 10, then on
15 − 7 = 15 − 5 − 2 = 8The same works for subtraction: first back to 10, then the rest.
Use what you know
3 + 4 = 713 + 4 = 17Without crossing 10, it is the sum to 10 with a ten in front.
Doubles and near doubles
7 + 7 = 147 + 8 = 15The doubles up to 10 + 10 help with all their neighbours.
Adding 9
9 + 6 = 10 + 6 − 1 = 15Adding 9 is adding 10 and taking away one.
Subtract by counting up
14 − 9 = 5, because 9 + 5 = 14When the numbers are close together, counting up is quicker than taking away.
Common mistakes
- 8 + 5 = 12↔8 + 5 = 13
A step gets lost when bridging through 10.
What helps: 8 + 2 = 10, then 3 more: 13.
- 14 − 6 = 12↔14 − 6 = 8
The ones get swapped: 6 − 4 instead of 14 − 6.
What helps: First take away 4 to get to 10, then 2 more: 8.
- 7 + 5 = 75
The digits are written next to each other instead of added.
What helps: Ask: how many are there altogether? Show it with counters or on a twenty frame.
For teachers
The sheet mixes problems with and without bridging through 10, so it fits the end of Year 1 / Grade 1 or revision at the start of Year 2 / Grade 2. The colouring version prints on any black-and-white photocopier, and the ink-saving version needs very little colour.
Rather practise with a game?
In Number Jungle your child runs through the jungle and dashes through the gate with the right answer. The same problems, matched to their school year, with no ads and offline. Free for Android, iPhone and iPad.
More about the game →FAQ
Which year group is this worksheet for?
From the second half of Year 1 / Grade 1, when numbers to 20 and bridging through 10 come up, and for revision in Year 2 / Grade 2.
Is the worksheet really free?
Yes. It is free, with no sign-up and no email address. You may print and copy it for home and for the classroom.
Is there an answer key?
No, on purpose. The inverse calculation is a good check: if your child worked out 8 − 3 = 5, they can check it with 5 + 3 = 8. For the gate problems, the right answer is one of the choices anyway.
What is the difference between the two versions?
The ink-saving version has animals in colour and a star to colour in. The colouring version is completely black and white, and the rescued animal itself gets coloured in.
How can my child keep practising bridging through 10?
Short, frequent practice helps most. For example with the free game Number Jungle: facts that are still wobbly come up more often until they stick.