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Missing Addends Within 20

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

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

__ + 20 = 20

2.

__ + 2 = 20

3.

__ + 1 = 20

4.

__ + 5 = 17

5.

__ + 5 = 20

6.

__ + 4 = 5

7.

__ + 1 = 11

8.

__ + 12 = 20

9.

__ + 2 = 10

10.

__ + 0 = 14

11.

__ + 10 = 15

12.

__ + 3 = 3

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 11
  1. __ + 20 = 200
  2. __ + 2 = 2018
  3. __ + 1 = 2019
  4. __ + 5 = 1712
  5. __ + 5 = 2015
  6. __ + 4 = 51
  7. __ + 1 = 1110
  8. __ + 12 = 208
  9. __ + 2 = 108
  10. __ + 0 = 1414
  11. __ + 10 = 155
  12. __ + 3 = 30

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.