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Missing Addends Within 20

Grade 1 · Stretch challenge · 12 questions · Version PG-13NEBM0-1OAJ

Four children and a teacher collaborate with blocks, patterns, and a notebook.
1.

__ + 5 = 12

2.

__ + 3 = 18

3.

__ + 5 = 5

4.

__ + 13 = 16

5.

__ + 8 = 20

6.

__ + 8 = 18

7.

__ + 0 = 20

8.

__ + 1 = 2

9.

__ + 14 = 18

10.

__ + 9 = 13

11.

__ + 15 = 18

12.

__ + 16 = 20

Answers and teaching notes

Use the answers to check the work after the learner finishes. For writing prompts, the guide describes what a strong response should include.

Show answers for version 10
  1. __ + 5 = 127
  2. __ + 3 = 1815
  3. __ + 5 = 50
  4. __ + 13 = 163
  5. __ + 8 = 2012
  6. __ + 8 = 1810
  7. __ + 0 = 2020
  8. __ + 1 = 21
  9. __ + 14 = 184
  10. __ + 9 = 134
  11. __ + 15 = 183
  12. __ + 16 = 204

Worked example

__ + 6 = 14. Think 14 - 6, so the missing addend is 8.

Common mistake

Adding the known addend and total together.

Helpful hint

Subtract the known part from the total.