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MathsAges 10-12

Missing-value equations

Find the missing value that makes an equation true, then check by substitution. Review suitability for your learners before teaching.

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Age band:Ages 7-9Ages 10-12

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Worksheet StudioPractice pack · Ages 10-12

Missing-value equations

Take your time. Show your thinking.

  1. 1. 12 × x + 13 = 157. Find x.

    LHS=RHS
    12 · 13 · 157 · Missing-value equations

  2. 2. 11 × x + 6 = 127. Find x.

    LHS=RHS
    11 · 6 · 127 · Missing-value equations

  3. 3. 8 × x + 7 = 71. Find x.

    LHS=RHS
    8 · 7 · 71 · Missing-value equations

  4. 4. 3 × x + 10 = 19. Find x.

    LHS=RHS
    3 · 10 · 19 · Missing-value equations

  5. 5. 7 × x + 9 = 58. Find x.

    LHS=RHS
    7 · 9 · 58 · Missing-value equations

  6. 6. 3 × x + 13 = 22. Find x.

    LHS=RHS
    3 · 13 · 22 · Missing-value equations

  7. 7. 4 × x + 17 = 33. Find x.

    LHS=RHS
    4 · 17 · 33 · Missing-value equations

  8. 8. 8 × x + 10 = 74. Find x.

    LHS=RHS
    8 · 10 · 74 · Missing-value equations

  9. 9. 3 × x + 19 = 28. Find x.

    LHS=RHS
    3 · 19 · 28 · Missing-value equations

  10. 10. 7 × x + 5 = 54. Find x.

    LHS=RHS
    7 · 5 · 54 · Missing-value equations

  11. 11. 12 × x + 15 = 159. Find x.

    LHS=RHS
    12 · 15 · 159 · Missing-value equations

  12. 12. 8 × x + 12 = 76. Find x.

    LHS=RHS
    8 · 12 · 76 · Missing-value equations
12 questions · Seed 49 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 10-12

Missing-value equations

Answers and reasoning. Review before teaching.

  1. 1. 12 × x + 13 = 157. Find x.

    12

    Subtract 13, then divide by 12: x = 12.

  2. 2. 11 × x + 6 = 127. Find x.

    11

    Subtract 6, then divide by 11: x = 11.

  3. 3. 8 × x + 7 = 71. Find x.

    8

    Subtract 7, then divide by 8: x = 8.

  4. 4. 3 × x + 10 = 19. Find x.

    3

    Subtract 10, then divide by 3: x = 3.

  5. 5. 7 × x + 9 = 58. Find x.

    7

    Subtract 9, then divide by 7: x = 7.

  6. 6. 3 × x + 13 = 22. Find x.

    3

    Subtract 13, then divide by 3: x = 3.

  7. 7. 4 × x + 17 = 33. Find x.

    4

    Subtract 17, then divide by 4: x = 4.

  8. 8. 8 × x + 10 = 74. Find x.

    8

    Subtract 10, then divide by 8: x = 8.

  9. 9. 3 × x + 19 = 28. Find x.

    3

    Subtract 19, then divide by 3: x = 3.

  10. 10. 7 × x + 5 = 54. Find x.

    7

    Subtract 5, then divide by 7: x = 7.

  11. 11. 12 × x + 15 = 159. Find x.

    12

    Subtract 15, then divide by 12: x = 12.

  12. 12. 8 × x + 12 = 76. Find x.

    8

    Subtract 12, then divide by 8: x = 8.

12 questions · Seed 49 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12

Missing-value equations

Take your time. Show your thinking.

  1. 1. 12 × x + 13 = 157. Find x.

    LHS=RHS
    12 · 13 · 157 · Missing-value equations

  2. 2. 11 × x + 6 = 127. Find x.

    LHS=RHS
    11 · 6 · 127 · Missing-value equations

  3. 3. 8 × x + 7 = 71. Find x.

    LHS=RHS
    8 · 7 · 71 · Missing-value equations

  4. 4. 3 × x + 10 = 19. Find x.

    LHS=RHS
    3 · 10 · 19 · Missing-value equations

  5. 5. 7 × x + 9 = 58. Find x.

    LHS=RHS
    7 · 9 · 58 · Missing-value equations

  6. 6. 3 × x + 13 = 22. Find x.

    LHS=RHS
    3 · 13 · 22 · Missing-value equations

  7. 7. 4 × x + 17 = 33. Find x.

    LHS=RHS
    4 · 17 · 33 · Missing-value equations

  8. 8. 8 × x + 10 = 74. Find x.

    LHS=RHS
    8 · 10 · 74 · Missing-value equations

  9. 9. 3 × x + 19 = 28. Find x.

    LHS=RHS
    3 · 19 · 28 · Missing-value equations

  10. 10. 7 × x + 5 = 54. Find x.

    LHS=RHS
    7 · 5 · 54 · Missing-value equations

  11. 11. 12 × x + 15 = 159. Find x.

    LHS=RHS
    12 · 15 · 159 · Missing-value equations

  12. 12. 8 × x + 12 = 76. Find x.

    LHS=RHS
    8 · 12 · 76 · Missing-value equations
12 questions · Seed 49 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12

Missing-value equations

Answers and reasoning. Review before teaching.

  1. 1. 12 × x + 13 = 157. Find x.

    12

    Subtract 13, then divide by 12: x = 12.

  2. 2. 11 × x + 6 = 127. Find x.

    11

    Subtract 6, then divide by 11: x = 11.

  3. 3. 8 × x + 7 = 71. Find x.

    8

    Subtract 7, then divide by 8: x = 8.

  4. 4. 3 × x + 10 = 19. Find x.

    3

    Subtract 10, then divide by 3: x = 3.

  5. 5. 7 × x + 9 = 58. Find x.

    7

    Subtract 9, then divide by 7: x = 7.

  6. 6. 3 × x + 13 = 22. Find x.

    3

    Subtract 13, then divide by 3: x = 3.

  7. 7. 4 × x + 17 = 33. Find x.

    4

    Subtract 17, then divide by 4: x = 4.

  8. 8. 8 × x + 10 = 74. Find x.

    8

    Subtract 10, then divide by 8: x = 8.

  9. 9. 3 × x + 19 = 28. Find x.

    3

    Subtract 19, then divide by 3: x = 3.

  10. 10. 7 × x + 5 = 54. Find x.

    7

    Subtract 5, then divide by 7: x = 7.

  11. 11. 12 × x + 15 = 159. Find x.

    12

    Subtract 15, then divide by 12: x = 12.

  12. 12. 8 × x + 12 = 76. Find x.

    8

    Subtract 12, then divide by 8: x = 8.

12 questions · Seed 49 · Age guidance, not curriculum certification