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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. 10 × x + 8 = 108. Find x.

    LHS=RHS
    10 · 8 · 108 · Missing-value equations

  2. 2. 4 × x + 7 = 23. Find x.

    LHS=RHS
    4 · 7 · 23 · Missing-value equations

  3. 3. 10 × x + 19 = 119. Find x.

    LHS=RHS
    10 · 19 · 119 · Missing-value equations

  4. 4. 5 × x + 17 = 42. Find x.

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

  5. 5. 5 × x + 20 = 45. Find x.

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

  6. 6. 9 × x + 7 = 88. Find x.

    LHS=RHS
    9 · 7 · 88 · Missing-value equations

  7. 7. 4 × x + 8 = 24. Find x.

    LHS=RHS
    4 · 8 · 24 · Missing-value equations

  8. 8. 3 × x + 16 = 25. Find x.

    LHS=RHS
    3 · 16 · 25 · Missing-value equations

  9. 9. 5 × x + 8 = 33. Find x.

    LHS=RHS
    5 · 8 · 33 · Missing-value equations

  10. 10. 6 × x + 15 = 51. Find x.

    LHS=RHS
    6 · 15 · 51 · Missing-value equations

  11. 11. 5 × x + 15 = 40. Find x.

    LHS=RHS
    5 · 15 · 40 · Missing-value equations

  12. 12. 5 × x + 18 = 43. Find x.

    LHS=RHS
    5 · 18 · 43 · Missing-value equations
12 questions · Seed 50 · 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. 10 × x + 8 = 108. Find x.

    10

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

  2. 2. 4 × x + 7 = 23. Find x.

    4

    Subtract 7, then divide by 4: x = 4.

  3. 3. 10 × x + 19 = 119. Find x.

    10

    Subtract 19, then divide by 10: x = 10.

  4. 4. 5 × x + 17 = 42. Find x.

    5

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

  5. 5. 5 × x + 20 = 45. Find x.

    5

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

  6. 6. 9 × x + 7 = 88. Find x.

    9

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

  7. 7. 4 × x + 8 = 24. Find x.

    4

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

  8. 8. 3 × x + 16 = 25. Find x.

    3

    Subtract 16, then divide by 3: x = 3.

  9. 9. 5 × x + 8 = 33. Find x.

    5

    Subtract 8, then divide by 5: x = 5.

  10. 10. 6 × x + 15 = 51. Find x.

    6

    Subtract 15, then divide by 6: x = 6.

  11. 11. 5 × x + 15 = 40. Find x.

    5

    Subtract 15, then divide by 5: x = 5.

  12. 12. 5 × x + 18 = 43. Find x.

    5

    Subtract 18, then divide by 5: x = 5.

12 questions · Seed 50 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12

Missing-value equations

Take your time. Show your thinking.

  1. 1. 10 × x + 8 = 108. Find x.

    LHS=RHS
    10 · 8 · 108 · Missing-value equations

  2. 2. 4 × x + 7 = 23. Find x.

    LHS=RHS
    4 · 7 · 23 · Missing-value equations

  3. 3. 10 × x + 19 = 119. Find x.

    LHS=RHS
    10 · 19 · 119 · Missing-value equations

  4. 4. 5 × x + 17 = 42. Find x.

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

  5. 5. 5 × x + 20 = 45. Find x.

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

  6. 6. 9 × x + 7 = 88. Find x.

    LHS=RHS
    9 · 7 · 88 · Missing-value equations

  7. 7. 4 × x + 8 = 24. Find x.

    LHS=RHS
    4 · 8 · 24 · Missing-value equations

  8. 8. 3 × x + 16 = 25. Find x.

    LHS=RHS
    3 · 16 · 25 · Missing-value equations

  9. 9. 5 × x + 8 = 33. Find x.

    LHS=RHS
    5 · 8 · 33 · Missing-value equations

  10. 10. 6 × x + 15 = 51. Find x.

    LHS=RHS
    6 · 15 · 51 · Missing-value equations

  11. 11. 5 × x + 15 = 40. Find x.

    LHS=RHS
    5 · 15 · 40 · Missing-value equations

  12. 12. 5 × x + 18 = 43. Find x.

    LHS=RHS
    5 · 18 · 43 · Missing-value equations
12 questions · Seed 50 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12

Missing-value equations

Answers and reasoning. Review before teaching.

  1. 1. 10 × x + 8 = 108. Find x.

    10

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

  2. 2. 4 × x + 7 = 23. Find x.

    4

    Subtract 7, then divide by 4: x = 4.

  3. 3. 10 × x + 19 = 119. Find x.

    10

    Subtract 19, then divide by 10: x = 10.

  4. 4. 5 × x + 17 = 42. Find x.

    5

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

  5. 5. 5 × x + 20 = 45. Find x.

    5

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

  6. 6. 9 × x + 7 = 88. Find x.

    9

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

  7. 7. 4 × x + 8 = 24. Find x.

    4

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

  8. 8. 3 × x + 16 = 25. Find x.

    3

    Subtract 16, then divide by 3: x = 3.

  9. 9. 5 × x + 8 = 33. Find x.

    5

    Subtract 8, then divide by 5: x = 5.

  10. 10. 6 × x + 15 = 51. Find x.

    6

    Subtract 15, then divide by 6: x = 6.

  11. 11. 5 × x + 15 = 40. Find x.

    5

    Subtract 15, then divide by 5: x = 5.

  12. 12. 5 × x + 18 = 43. Find x.

    5

    Subtract 18, then divide by 5: x = 5.

12 questions · Seed 50 · Age guidance, not curriculum certification