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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. 5 × x + 17 = 42. Find x.

    LHS=RHS
    5 · 17 · 42 · Missing-value equations

  2. 2. 8 × x + 10 = 74. Find x.

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

  3. 3. 12 × x + 15 = 159. Find x.

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

  4. 4. 10 × x + 10 = 110. Find x.

    LHS=RHS
    10 · 10 · 110 · Missing-value equations

  5. 5. 11 × x + 19 = 140. Find x.

    LHS=RHS
    11 · 19 · 140 · Missing-value equations

  6. 6. 12 × x + 16 = 160. Find x.

    LHS=RHS
    12 · 16 · 160 · Missing-value equations

  7. 7. 8 × x + 7 = 71. Find x.

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

  8. 8. 4 × x + 10 = 26. Find x.

    LHS=RHS
    4 · 10 · 26 · Missing-value equations

  9. 9. 2 × x + 16 = 20. Find x.

    LHS=RHS
    2 · 16 · 20 · Missing-value equations

  10. 10. 4 × x + 16 = 32. Find x.

    LHS=RHS
    4 · 16 · 32 · Missing-value equations

  11. 11. 10 × x + 13 = 113. Find x.

    LHS=RHS
    10 · 13 · 113 · Missing-value equations

  12. 12. 4 × x + 15 = 31. Find x.

    LHS=RHS
    4 · 15 · 31 · Missing-value equations
12 questions · Seed 48 · 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. 5 × x + 17 = 42. Find x.

    5

    Subtract 17, then divide by 5: x = 5.

  2. 2. 8 × x + 10 = 74. Find x.

    8

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

  3. 3. 12 × x + 15 = 159. Find x.

    12

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

  4. 4. 10 × x + 10 = 110. Find x.

    10

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

  5. 5. 11 × x + 19 = 140. Find x.

    11

    Subtract 19, then divide by 11: x = 11.

  6. 6. 12 × x + 16 = 160. Find x.

    12

    Subtract 16, then divide by 12: x = 12.

  7. 7. 8 × x + 7 = 71. Find x.

    8

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

  8. 8. 4 × x + 10 = 26. Find x.

    4

    Subtract 10, then divide by 4: x = 4.

  9. 9. 2 × x + 16 = 20. Find x.

    2

    Subtract 16, then divide by 2: x = 2.

  10. 10. 4 × x + 16 = 32. Find x.

    4

    Subtract 16, then divide by 4: x = 4.

  11. 11. 10 × x + 13 = 113. Find x.

    10

    Subtract 13, then divide by 10: x = 10.

  12. 12. 4 × x + 15 = 31. Find x.

    4

    Subtract 15, then divide by 4: x = 4.

12 questions · Seed 48 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12

Missing-value equations

Take your time. Show your thinking.

  1. 1. 5 × x + 17 = 42. Find x.

    LHS=RHS
    5 · 17 · 42 · Missing-value equations

  2. 2. 8 × x + 10 = 74. Find x.

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

  3. 3. 12 × x + 15 = 159. Find x.

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

  4. 4. 10 × x + 10 = 110. Find x.

    LHS=RHS
    10 · 10 · 110 · Missing-value equations

  5. 5. 11 × x + 19 = 140. Find x.

    LHS=RHS
    11 · 19 · 140 · Missing-value equations

  6. 6. 12 × x + 16 = 160. Find x.

    LHS=RHS
    12 · 16 · 160 · Missing-value equations

  7. 7. 8 × x + 7 = 71. Find x.

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

  8. 8. 4 × x + 10 = 26. Find x.

    LHS=RHS
    4 · 10 · 26 · Missing-value equations

  9. 9. 2 × x + 16 = 20. Find x.

    LHS=RHS
    2 · 16 · 20 · Missing-value equations

  10. 10. 4 × x + 16 = 32. Find x.

    LHS=RHS
    4 · 16 · 32 · Missing-value equations

  11. 11. 10 × x + 13 = 113. Find x.

    LHS=RHS
    10 · 13 · 113 · Missing-value equations

  12. 12. 4 × x + 15 = 31. Find x.

    LHS=RHS
    4 · 15 · 31 · Missing-value equations
12 questions · Seed 48 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12

Missing-value equations

Answers and reasoning. Review before teaching.

  1. 1. 5 × x + 17 = 42. Find x.

    5

    Subtract 17, then divide by 5: x = 5.

  2. 2. 8 × x + 10 = 74. Find x.

    8

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

  3. 3. 12 × x + 15 = 159. Find x.

    12

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

  4. 4. 10 × x + 10 = 110. Find x.

    10

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

  5. 5. 11 × x + 19 = 140. Find x.

    11

    Subtract 19, then divide by 11: x = 11.

  6. 6. 12 × x + 16 = 160. Find x.

    12

    Subtract 16, then divide by 12: x = 12.

  7. 7. 8 × x + 7 = 71. Find x.

    8

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

  8. 8. 4 × x + 10 = 26. Find x.

    4

    Subtract 10, then divide by 4: x = 4.

  9. 9. 2 × x + 16 = 20. Find x.

    2

    Subtract 16, then divide by 2: x = 2.

  10. 10. 4 × x + 16 = 32. Find x.

    4

    Subtract 16, then divide by 4: x = 4.

  11. 11. 10 × x + 13 = 113. Find x.

    10

    Subtract 13, then divide by 10: x = 10.

  12. 12. 4 × x + 15 = 31. Find x.

    4

    Subtract 15, then divide by 4: x = 4.

12 questions · Seed 48 · Age guidance, not curriculum certification