Finding the missing number

Mathematics · Addition & Subtraction · ages 6-7

Name ______________________ Date ____________

Count the hops from 8 to 10 on the number line. How many hops is that?
- 1
- 2
- 3
10 - ? = 6. What is the missing number?
- 3
- 5
- 2
- 4
7 + ? = 12. What is the missing number?
Answer: ______________
10 − 8 = ? is the same as asking which question?
- 8 + ? = 10
- 10 + ? = 8
- 8 − ? = 10
Ben says 5 + ? = 13 means ? = 7. Is Ben right?
Circle one: True False
? - 3 = 8. What is the missing number?
- 11
- 10
- 12
- 9
6 + ? = 15. What is the missing number?
Answer: ______________
Leo has 8 stickers and wants 10 in total. He thinks: 8 + ? = 10. How many more does he need?
- 1
- 2
- 3
Sam solves 10 − 7 by thinking 7 + ? = 10, and says the answer is 4. What went wrong?
- He should have added 7 + 10 instead
- Nothing, 4 is correct
- He counted one hop too many, the answer is 3
? + 6 = 11 and 11 - 6 = ? have the same missing number, 5. Is that right?
Circle one: True False

Answer key

For grown-ups. Fold this page away before handing over the rest.

2 · 8 hops to 10 in 2 steps, so 8 + 2 = 10 and 10 − 8 = 2.
4 · Think 6 + ? = 10, and 6 + 4 = 10.
5 · 7 + 5 = 12.
8 + ? = 10 · Subtraction can be rewritten as a missing-addend question: what added to 8 makes 10?
False · Ben is wrong: 13 - 5 = 8, so ? = 8.
11 · Think 8 + 3 = 11.
9 · 6 + 9 = 15, using the known fact family.
2 · 8 + 2 = 10, so Leo needs 2 more stickers.
He counted one hop too many, the answer is 3 · 7 + 3 = 10, not 7 + 4. Sam counted an extra hop by mistake.
True · Right: 5 + 6 = 11 and 11 - 6 = 5.