About
A maths game for Year 2 built on the part-whole model that UK schools use for adding and taking away (the "cherry" with the whole on top and two parts below). Read the sum, find its three numbers among the circles on the page and draw a line from the whole to each part. Then draw a line from the answer to the box with the same number for 5 points. A finished model shrinks into a small cherry at the top of the page. 40 levels of three sums, mixed from level 4 on: adding, taking away and missing parts within 10, then within 20, then two-digit numbers split into tens and ones (24 = 20 + 4) and taken apart again (24 - 4, 24 - 20). On the last sum of every level the circles drift slowly. No clock, and fewer wrong lines mean more stars.
For parents and teachers
What the part-whole model is
- 6 + 4 = 10
- 4 + 6 = 10
- 10 − 6 = 4
- 10 − 4 = 6
The part-whole model is a picture of one number split into two parts: the whole sits on top and the two parts sit below, joined by lines. Children in English primary schools often call it the cherry.
Schools use it so children see that one picture holds four facts. 6 and 4 make 10, so 6 + 4 = 10, 4 + 6 = 10, 10 − 6 = 4 and 10 − 4 = 6. That group is called a fact family.
How to play
1. Build the cherryRead the sum and find its three numbers among the circles. Draw a line from the whole to each part.
2. Join the answer to its boxDraw a line from the answer to the box with the same number. Each finished sum gives 5 points.
3. The cherry goes to the topThe finished model shrinks into a small cherry at the top of the page, and the next sum starts.
What each level block practises
| Levels | Practises | Example |
|---|---|---|
| 1 to 3 | Adding within 10, to warm up | 4 + 2 = ? |
| 4 to 10 | Adding, taking away and missing parts within 10, mixed in every level | 9 − 3 = ? |
| 11 to 20 | The same mix within 20, with teen numbers split into tens and ones | 14 = 10 + ? |
| 21 to 30 | The mix within 20, plus two-digit numbers split into tens and ones | 46 = ? + 6 |
| 31 to 40 | Everything mixed, plus taking the ones or the tens away | 24 − 4 = ? |
Three sums a level. On the last sum of every level the circles drift slowly.
The national curriculum link
These are statutory requirements for Year 2 in the national curriculum in England (mathematics, Year 2, Number). The part-whole picture in Cherry Sums gives practice for them:
recall and use addition and subtraction facts to 20 fluently, and derive and use related facts up to 100
show that addition of 2 numbers can be done in any order (commutative) and subtraction of 1 number from another cannot
recognise and use the inverse relationship between addition and subtraction and use this to check calculations and solve missing number problems
solve problems with addition and subtraction: using concrete objects and pictorial representations, including those involving numbers, quantities and measures
recognise the place value of each digit in a two-digit number (10s, 1s)
Adding and taking away stay within 20; tens and ones go up to 99. Cherry Sums does not cover adding two two-digit numbers.
Notes for grown-ups
- About 10 minutes at a time is plenty. A level is three sums.
- There is no timer, on purpose. Counting on fingers is fine.
- A wrong line costs a star, never points. No wrong lines in a level earns 3 stars, one or two earn 2, more earn 1.
- Levels open one by one as they are won, and any open level can be played again for more stars.
- Progress is saved in the browser. If a grown-up signs in on this site, progress also follows the account to other devices. Signing in is optional: the game works without it.
Privacy
- The game has no accounts, no chat and no ads, and it never asks for a name.
- It sends anonymous play events to its own server: a level started or ended, the stars, how many wrong lines were drawn, how long it took, the screen size and the game version, with a random id made on the device. The server does not store IP addresses.
- This site asks before it sets any analytics cookies. Signing in is optional and meant for grown-ups.
More detail: the site privacy policy and the game's privacy note.