Number sentences with a missing number
Name: _____________________ Date: __________
Show your thinking with numbers, words, or a drawing.
1. What number goes in the box? □ + 7 = 13
2. What number goes in the box? □ + 7 = 16
3. What number goes in the box? □ + 9 = 13
4. What number goes in the box? 12 + □ = 18
5. What number goes in the box? 9 + □ = 12
Answer key · Number sentences with a missing number
1. 6
The box is the part that goes with 7 to make 13.
Use the inverse: 13 − 7 = 6.
6 + 7 = 13, so the box is 6.
2. 9
The box is the part that goes with 7 to make 16.
Use the inverse: 16 − 7 = 9.
9 + 7 = 16, so the box is 9.
3. 4
The box is the part that goes with 9 to make 13.
Use the inverse: 13 − 9 = 4.
4 + 9 = 13, so the box is 4.
4. 6
The box is the part that goes with 12 to make 18.
Use the inverse: 18 − 12 = 6.
12 + 6 = 18, so the box is 6.
5. 3
The box is the part that goes with 9 to make 12.
Use the inverse: 12 − 9 = 3.
9 + 3 = 12, so the box is 3.
Try it together
Choose a question from the printable. Use objects or a drawing to show your thinking, then explain your method to someone at home.