Doubles
Doubles Facts: 1 + 1 to 10 + 10
Ten facts that are easy to remember, and they unlock the near doubles next door.
The doubles
| Double | A picture to remember it | Next door |
|---|---|---|
| 1 + 1 = 2 | Two eyes, one on each side | 1 + 2 = 3 |
| 2 + 2 = 4 | A car's wheels: two on each side | 2 + 3 = 5 |
| 3 + 3 = 6 | An insect's legs: three on each side | 3 + 4 = 7 |
| 4 + 4 = 8 | A spider's legs: four on each side | 4 + 5 = 9 |
| 5 + 5 = 10 | Fingers on two hands | 5 + 6 = 11 |
| 6 + 6 = 12 | An egg box: two rows of six | 6 + 7 = 13 |
| 7 + 7 = 14 | Two weeks of seven days | 7 + 8 = 15 |
| 8 + 8 = 16 | Two boxes of eight crayons | 8 + 9 = 17 |
| 9 + 9 = 18 | Two less than 10 + 10 | 9 + 10 = 19 |
| 10 + 10 = 20 | Fingers and toes | — |
Why doubles earn their place
Children remember doubles sooner than most facts. There's something satisfying about two equal groups.
6 + 7 is 6 + 6 and one more. Once a child knows the ten doubles, eighteen more facts are within reach.
If 8 + 8 = 16, then 16 − 8 = 8 and half of 16 is 8. See the guide to doubles and near doubles.
Play the doubles game
Doubles and the halves that go with them
Free to play · no signup · works on phones, tablets and computers
Quick quiz
Doubles FAQ
What are doubles facts in math?
Sums where both numbers are the same, like 4 + 4 or 7 + 7.
What's a near double?
A sum of two neighbors, like 6 + 7. It's a double plus 1.
Is Sumtown really free?
Yes. The whole game plays free in your browser, with no signup, no ads and no time limit. All fourteen mini games are in it. An iPhone app is on its way, and you can read what it will add.
An app is on its way
We're building a Sumtown app for iPhone with the parts that need a real app: offline play for car rides, a town map that remembers how far your child got, and a parent report on every fact. Until then, the whole game is free right here.
Coming soon on theApp Store