Missing Numbers

Find the unknown: 9 + ? = 15, ? − 4 = 8.

Warm-up, learn, try it together, practice, then a quick check. About 15 minutes.

What children learn in Level 7

Sometimes a number is hiding! The question mark stands for the number we need to find.
9 plus what makes 15? Count up from 9 to 15: 1 gets to 10, then 5 more. That's 6.
Now try this one: what number, take away 4, leaves 8? Think backwards: 8 plus 4 is 12. The hiding number is 12!
Your turn: 7 plus what makes 11? Tap to count up from 7. Stop at 10 on the way!
3 and 1 more is 4. So 7 plus 4 makes 11! Fact families help you find hiding numbers.

Georgia's K-12 Mathematics Standards:

2.NR.2.1 — Fluently add and subtract within 20 using a variety of mental, part-whole strategies.