PencilGoPencilGo

Missing Addends Within 20

Grade 1 · Stretch challenge · 12 questions · Version PG-14RCQDW-1OAJ

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

__ + 9 = 20

2.

__ + 5 = 20

3.

__ + 8 = 15

4.

__ + 4 = 20

5.

__ + 2 = 3

6.

__ + 16 = 20

7.

__ + 12 = 12

8.

__ + 2 = 4

9.

__ + 3 = 9

10.

__ + 7 = 20

11.

__ + 1 = 20

12.

__ + 15 = 18

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 14
  1. __ + 9 = 2011
  2. __ + 5 = 2015
  3. __ + 8 = 157
  4. __ + 4 = 2016
  5. __ + 2 = 31
  6. __ + 16 = 204
  7. __ + 12 = 120
  8. __ + 2 = 42
  9. __ + 3 = 96
  10. __ + 7 = 2013
  11. __ + 1 = 2019
  12. __ + 15 = 183

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.