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MathsAges 13-15

Lowest common multiple (LCM)

Find the lowest common multiple (LCM) shared by two whole numbers. Review suitability for your learners before teaching.

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Age band:Ages 10-12Ages 13-15

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Worksheet StudioPractice pack · Ages 13-15

Lowest common multiple (LCM)

Take your time. Show your thinking.

  1. 1. What is the lowest common multiple (LCM) of 6 and 21?

    6 · 21 · Lowest common multiple (LCM)

  2. 2. What is the lowest common multiple (LCM) of 18 and 24?

    18 · 24 · Lowest common multiple (LCM)

  3. 3. What is the lowest common multiple (LCM) of 15 and 25?

    15 · 25 · Lowest common multiple (LCM)

  4. 4. What is the lowest common multiple (LCM) of 36 and 84?

    36 · 84 · Lowest common multiple (LCM)

  5. 5. What is the lowest common multiple (LCM) of 9 and 12?

    9 · 12 · Lowest common multiple (LCM)

  6. 6. What is the lowest common multiple (LCM) of 24 and 84?

    24 · 84 · Lowest common multiple (LCM)

  7. 7. What is the lowest common multiple (LCM) of 44 and 55?

    44 · 55 · Lowest common multiple (LCM)

  8. 8. What is the lowest common multiple (LCM) of 27 and 45?

    27 · 45 · Lowest common multiple (LCM)

  9. 9. What is the lowest common multiple (LCM) of 25 and 30?

    25 · 30 · Lowest common multiple (LCM)

  10. 10. What is the lowest common multiple (LCM) of 21 and 35?

    21 · 35 · Lowest common multiple (LCM)

  11. 11. What is the lowest common multiple (LCM) of 35 and 49?

    35 · 49 · Lowest common multiple (LCM)

  12. 12. What is the lowest common multiple (LCM) of 20 and 24?

    20 · 24 · Lowest common multiple (LCM)
12 questions · Seed 50 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 13-15

Lowest common multiple (LCM)

Answers and reasoning. Review before teaching.

  1. 1. What is the lowest common multiple (LCM) of 6 and 21?

    42

    The highest common factor of 6 and 21 is 3, so LCM = (6 × 21) ÷ 3 = 42.

  2. 2. What is the lowest common multiple (LCM) of 18 and 24?

    72

    The highest common factor of 18 and 24 is 6, so LCM = (18 × 24) ÷ 6 = 72.

  3. 3. What is the lowest common multiple (LCM) of 15 and 25?

    75

    The highest common factor of 15 and 25 is 5, so LCM = (15 × 25) ÷ 5 = 75.

  4. 4. What is the lowest common multiple (LCM) of 36 and 84?

    252

    The highest common factor of 36 and 84 is 12, so LCM = (36 × 84) ÷ 12 = 252.

  5. 5. What is the lowest common multiple (LCM) of 9 and 12?

    36

    The highest common factor of 9 and 12 is 3, so LCM = (9 × 12) ÷ 3 = 36.

  6. 6. What is the lowest common multiple (LCM) of 24 and 84?

    168

    The highest common factor of 24 and 84 is 12, so LCM = (24 × 84) ÷ 12 = 168.

  7. 7. What is the lowest common multiple (LCM) of 44 and 55?

    220

    The highest common factor of 44 and 55 is 11, so LCM = (44 × 55) ÷ 11 = 220.

  8. 8. What is the lowest common multiple (LCM) of 27 and 45?

    135

    The highest common factor of 27 and 45 is 9, so LCM = (27 × 45) ÷ 9 = 135.

  9. 9. What is the lowest common multiple (LCM) of 25 and 30?

    150

    The highest common factor of 25 and 30 is 5, so LCM = (25 × 30) ÷ 5 = 150.

  10. 10. What is the lowest common multiple (LCM) of 21 and 35?

    105

    The highest common factor of 21 and 35 is 7, so LCM = (21 × 35) ÷ 7 = 105.

  11. 11. What is the lowest common multiple (LCM) of 35 and 49?

    245

    The highest common factor of 35 and 49 is 7, so LCM = (35 × 49) ÷ 7 = 245.

  12. 12. What is the lowest common multiple (LCM) of 20 and 24?

    120

    The highest common factor of 20 and 24 is 4, so LCM = (20 × 24) ÷ 4 = 120.

12 questions · Seed 50 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 13-15

Lowest common multiple (LCM)

Take your time. Show your thinking.

  1. 1. What is the lowest common multiple (LCM) of 6 and 21?

    6 · 21 · Lowest common multiple (LCM)

  2. 2. What is the lowest common multiple (LCM) of 18 and 24?

    18 · 24 · Lowest common multiple (LCM)

  3. 3. What is the lowest common multiple (LCM) of 15 and 25?

    15 · 25 · Lowest common multiple (LCM)

  4. 4. What is the lowest common multiple (LCM) of 36 and 84?

    36 · 84 · Lowest common multiple (LCM)

  5. 5. What is the lowest common multiple (LCM) of 9 and 12?

    9 · 12 · Lowest common multiple (LCM)

  6. 6. What is the lowest common multiple (LCM) of 24 and 84?

    24 · 84 · Lowest common multiple (LCM)

  7. 7. What is the lowest common multiple (LCM) of 44 and 55?

    44 · 55 · Lowest common multiple (LCM)

  8. 8. What is the lowest common multiple (LCM) of 27 and 45?

    27 · 45 · Lowest common multiple (LCM)

  9. 9. What is the lowest common multiple (LCM) of 25 and 30?

    25 · 30 · Lowest common multiple (LCM)

  10. 10. What is the lowest common multiple (LCM) of 21 and 35?

    21 · 35 · Lowest common multiple (LCM)

  11. 11. What is the lowest common multiple (LCM) of 35 and 49?

    35 · 49 · Lowest common multiple (LCM)

  12. 12. What is the lowest common multiple (LCM) of 20 and 24?

    20 · 24 · Lowest common multiple (LCM)
12 questions · Seed 50 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 13-15

Lowest common multiple (LCM)

Answers and reasoning. Review before teaching.

  1. 1. What is the lowest common multiple (LCM) of 6 and 21?

    42

    The highest common factor of 6 and 21 is 3, so LCM = (6 × 21) ÷ 3 = 42.

  2. 2. What is the lowest common multiple (LCM) of 18 and 24?

    72

    The highest common factor of 18 and 24 is 6, so LCM = (18 × 24) ÷ 6 = 72.

  3. 3. What is the lowest common multiple (LCM) of 15 and 25?

    75

    The highest common factor of 15 and 25 is 5, so LCM = (15 × 25) ÷ 5 = 75.

  4. 4. What is the lowest common multiple (LCM) of 36 and 84?

    252

    The highest common factor of 36 and 84 is 12, so LCM = (36 × 84) ÷ 12 = 252.

  5. 5. What is the lowest common multiple (LCM) of 9 and 12?

    36

    The highest common factor of 9 and 12 is 3, so LCM = (9 × 12) ÷ 3 = 36.

  6. 6. What is the lowest common multiple (LCM) of 24 and 84?

    168

    The highest common factor of 24 and 84 is 12, so LCM = (24 × 84) ÷ 12 = 168.

  7. 7. What is the lowest common multiple (LCM) of 44 and 55?

    220

    The highest common factor of 44 and 55 is 11, so LCM = (44 × 55) ÷ 11 = 220.

  8. 8. What is the lowest common multiple (LCM) of 27 and 45?

    135

    The highest common factor of 27 and 45 is 9, so LCM = (27 × 45) ÷ 9 = 135.

  9. 9. What is the lowest common multiple (LCM) of 25 and 30?

    150

    The highest common factor of 25 and 30 is 5, so LCM = (25 × 30) ÷ 5 = 150.

  10. 10. What is the lowest common multiple (LCM) of 21 and 35?

    105

    The highest common factor of 21 and 35 is 7, so LCM = (21 × 35) ÷ 7 = 105.

  11. 11. What is the lowest common multiple (LCM) of 35 and 49?

    245

    The highest common factor of 35 and 49 is 7, so LCM = (35 × 49) ÷ 7 = 245.

  12. 12. What is the lowest common multiple (LCM) of 20 and 24?

    120

    The highest common factor of 20 and 24 is 4, so LCM = (20 × 24) ÷ 4 = 120.

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