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Missing factor: 3rd grade math

Unknown factor; division as an unknown-factor problem. A free 3rd grade lesson plan, a question set with answers and a printable sheet with its key. Copy it and make it yours.

Lesson plan

Goal

  • Students can do this: unknown factor; division as an unknown-factor problem.

Teach (10 min)

  • ? × 4 = 28 asks: how many 4s make 28?
  • Count by 4s until you reach 28: that's 7 of them.
  • Work one example on the board while students say each step aloud, then do one together.

Practise (15 min)

  • Students work the printable sheet in pairs, then alone.
  • Or practise it as a game with no sign-up: https://peabody.kids/math/whole.unknown?lesson=3-missing&at=3

Exit ticket (5 min)

  • Three questions on a slip:
  • 1. 2 × ? = 4
  • 2. ? × 3 = 12
  • 3. ? × 5 = 20

Question set

10 questions that read in words, easiest first. Questions that need a picture are on the printable sheet below.

  1. 2 × ? = 4
  2. ? × 3 = 12
  3. ? × 5 = 20
  4. ? × 2 = 8
  5. 4 × ? = 16
  6. 5 × ? = 10
  7. 4 × ? = 28
  8. ? × 4 = 16
  9. 24 ÷ ? = 3
  10. 8 × ? = 32
Answers
  1. 2
  2. 4
  3. 4
  4. 4
  5. 4
  6. 2
  7. 7
  8. 4
  9. 8
  10. 4

Printable sheet

Name: ____________________   Date: ____________

Missing factor (3rd grade)

  1. ? × 3 = 9
  2. ? × 2 = 4
  3. 4 × ? = 20
  4. ? × 2 = 4
  5. 6 × ? = 12
  6. 28 ÷ ? = 4
  7. ? × 5 = 15
  8. 20 ÷ ? = 5
  9. ? ÷ 5 = 4
  10. ? × 9 = 54
  11. ? × 5 = 35
  12. ? × 6 = 36
Key
  1. 3
  2. 2
  3. 5
  4. 2
  5. 2
  6. 7
  7. 3
  8. 4
  9. 20
  10. 6
  11. 7
  12. 6

Written by Peabody from its own skill pages. Free, no ads, no sign-in. Children can practise this on Peabody. More from teachers: teacher-shared resources.