Subtraction fact · near doubles
17 − 8 = 9
Seventeen minus eight is nine. Ask the addition question instead: 8 + what makes 17?
See 17 − 8
17 counters, 8 crossed out, 9 left.
Think of a double
- Find the nearest double: 8 + 8 = 16.
- 17 is one more than 16, so the missing number is one more than 8.
- 8 + 9 = 17, so 17 − 8 = 9.
Its fact family
8, 9 and 17 go together, so learning one of these helps with all of them. See the family.
Practice 17 − 8 in a game
A fact sticks when a child has to pull it from memory again and again. In this game 17 − 8 keeps coming back between the other facts in its family.
Every round leans on 17 − 8
Free to play · no signup · works on phones, tablets and computers
Quick quiz
17 − 8 FAQ
What is 17 − 8?
17 − 8 = 9. In words: seventeen minus eight is nine.
How can I check 17 − 8 = 9?
Add back: 9 + 8 = 17. If the addition gives the number you started with, the subtraction is right.
What grade learns 17 − 8?
This is a first and second grade fact. Common Core has children subtract within 20 in first grade (1.OA.C.6) and do it fluently with mental strategies in second grade (2.OA.B.2).
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