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Missing Addends Within 20

Grade 1 · Building confidence · 12 questions · Version PG-L8A7NH-RBT8

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

__ + 20 = 20

2.

__ + 13 = 17

3.

__ + 13 = 20

4.

__ + 2 = 12

5.

__ + 8 = 20

6.

__ + 14 = 20

7.

__ + 3 = 17

8.

__ + 3 = 20

9.

__ + 18 = 18

10.

__ + 9 = 20

11.

__ + 2 = 20

12.

__ + 8 = 16

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 8
  1. __ + 20 = 200
  2. __ + 13 = 174
  3. __ + 13 = 207
  4. __ + 2 = 1210
  5. __ + 8 = 2012
  6. __ + 14 = 206
  7. __ + 3 = 1714
  8. __ + 3 = 2017
  9. __ + 18 = 180
  10. __ + 9 = 2011
  11. __ + 2 = 2018
  12. __ + 8 = 168

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.