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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. 8 × x + 2 = 66. Find x.

    LHS=RHS
    8 · 2 · 66 · Missing-value equations

  2. 2. 9 × x + 10 = 91. Find x.

    LHS=RHS
    9 · 10 · 91 · Missing-value equations

  3. 3. 3 × x + 12 = 21. Find x.

    LHS=RHS
    3 · 12 · 21 · Missing-value equations

  4. 4. 7 × x + 10 = 59. Find x.

    LHS=RHS
    7 · 10 · 59 · Missing-value equations

  5. 5. 11 × x + 17 = 138. Find x.

    LHS=RHS
    11 · 17 · 138 · Missing-value equations

  6. 6. 5 × x + 20 = 45. Find x.

    LHS=RHS
    5 · 20 · 45 · Missing-value equations

  7. 7. 8 × x + 19 = 83. Find x.

    LHS=RHS
    8 · 19 · 83 · Missing-value equations

  8. 8. 8 × x + 4 = 68. Find x.

    LHS=RHS
    8 · 4 · 68 · Missing-value equations

  9. 9. 3 × x + 11 = 20. Find x.

    LHS=RHS
    3 · 11 · 20 · Missing-value equations

  10. 10. 8 × x + 10 = 74. Find x.

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

  11. 11. 4 × x + 3 = 19. Find x.

    LHS=RHS
    4 · 3 · 19 · Missing-value equations

  12. 12. 8 × x + 18 = 82. Find x.

    LHS=RHS
    8 · 18 · 82 · Missing-value equations
12 questions · Seed 104731 · 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. 8 × x + 2 = 66. Find x.

    8

    Subtract 2, then divide by 8: x = 8.

  2. 2. 9 × x + 10 = 91. Find x.

    9

    Subtract 10, then divide by 9: x = 9.

  3. 3. 3 × x + 12 = 21. Find x.

    3

    Subtract 12, then divide by 3: x = 3.

  4. 4. 7 × x + 10 = 59. Find x.

    7

    Subtract 10, then divide by 7: x = 7.

  5. 5. 11 × x + 17 = 138. Find x.

    11

    Subtract 17, then divide by 11: x = 11.

  6. 6. 5 × x + 20 = 45. Find x.

    5

    Subtract 20, then divide by 5: x = 5.

  7. 7. 8 × x + 19 = 83. Find x.

    8

    Subtract 19, then divide by 8: x = 8.

  8. 8. 8 × x + 4 = 68. Find x.

    8

    Subtract 4, then divide by 8: x = 8.

  9. 9. 3 × x + 11 = 20. Find x.

    3

    Subtract 11, then divide by 3: x = 3.

  10. 10. 8 × x + 10 = 74. Find x.

    8

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

  11. 11. 4 × x + 3 = 19. Find x.

    4

    Subtract 3, then divide by 4: x = 4.

  12. 12. 8 × x + 18 = 82. Find x.

    8

    Subtract 18, then divide by 8: x = 8.

12 questions · Seed 104731 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12

Missing-value equations

Take your time. Show your thinking.

  1. 1. 8 × x + 2 = 66. Find x.

    LHS=RHS
    8 · 2 · 66 · Missing-value equations

  2. 2. 9 × x + 10 = 91. Find x.

    LHS=RHS
    9 · 10 · 91 · Missing-value equations

  3. 3. 3 × x + 12 = 21. Find x.

    LHS=RHS
    3 · 12 · 21 · Missing-value equations

  4. 4. 7 × x + 10 = 59. Find x.

    LHS=RHS
    7 · 10 · 59 · Missing-value equations

  5. 5. 11 × x + 17 = 138. Find x.

    LHS=RHS
    11 · 17 · 138 · Missing-value equations

  6. 6. 5 × x + 20 = 45. Find x.

    LHS=RHS
    5 · 20 · 45 · Missing-value equations

  7. 7. 8 × x + 19 = 83. Find x.

    LHS=RHS
    8 · 19 · 83 · Missing-value equations

  8. 8. 8 × x + 4 = 68. Find x.

    LHS=RHS
    8 · 4 · 68 · Missing-value equations

  9. 9. 3 × x + 11 = 20. Find x.

    LHS=RHS
    3 · 11 · 20 · Missing-value equations

  10. 10. 8 × x + 10 = 74. Find x.

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

  11. 11. 4 × x + 3 = 19. Find x.

    LHS=RHS
    4 · 3 · 19 · Missing-value equations

  12. 12. 8 × x + 18 = 82. Find x.

    LHS=RHS
    8 · 18 · 82 · Missing-value equations
12 questions · Seed 104731 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12

Missing-value equations

Answers and reasoning. Review before teaching.

  1. 1. 8 × x + 2 = 66. Find x.

    8

    Subtract 2, then divide by 8: x = 8.

  2. 2. 9 × x + 10 = 91. Find x.

    9

    Subtract 10, then divide by 9: x = 9.

  3. 3. 3 × x + 12 = 21. Find x.

    3

    Subtract 12, then divide by 3: x = 3.

  4. 4. 7 × x + 10 = 59. Find x.

    7

    Subtract 10, then divide by 7: x = 7.

  5. 5. 11 × x + 17 = 138. Find x.

    11

    Subtract 17, then divide by 11: x = 11.

  6. 6. 5 × x + 20 = 45. Find x.

    5

    Subtract 20, then divide by 5: x = 5.

  7. 7. 8 × x + 19 = 83. Find x.

    8

    Subtract 19, then divide by 8: x = 8.

  8. 8. 8 × x + 4 = 68. Find x.

    8

    Subtract 4, then divide by 8: x = 8.

  9. 9. 3 × x + 11 = 20. Find x.

    3

    Subtract 11, then divide by 3: x = 3.

  10. 10. 8 × x + 10 = 74. Find x.

    8

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

  11. 11. 4 × x + 3 = 19. Find x.

    4

    Subtract 3, then divide by 4: x = 4.

  12. 12. 8 × x + 18 = 82. Find x.

    8

    Subtract 18, then divide by 8: x = 8.

12 questions · Seed 104731 · Age guidance, not curriculum certification