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Missing Addends Within 20

Grade 1 · Stretch challenge · 12 questions · Version PG-T92R3C-1OAJ

1.

__ + 1 = 20

2.

__ + 9 = 17

3.

__ + 4 = 20

4.

__ + 10 = 18

5.

__ + 9 = 14

6.

__ + 1 = 8

7.

__ + 13 = 16

8.

__ + 4 = 16

9.

__ + 9 = 16

10.

__ + 7 = 20

11.

__ + 8 = 17

12.

__ + 9 = 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 1
  1. __ + 1 = 2019
  2. __ + 9 = 178
  3. __ + 4 = 2016
  4. __ + 10 = 188
  5. __ + 9 = 145
  6. __ + 1 = 87
  7. __ + 13 = 163
  8. __ + 4 = 1612
  9. __ + 9 = 167
  10. __ + 7 = 2013
  11. __ + 8 = 179
  12. __ + 9 = 2011

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.