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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 55 and 66?

    55 · 66 · Lowest common multiple (LCM)

  2. 2. What is the lowest common multiple (LCM) of 20 and 28?

    20 · 28 · Lowest common multiple (LCM)

  3. 3. What is the lowest common multiple (LCM) of 16 and 40?

    16 · 40 · Lowest common multiple (LCM)

  4. 4. What is the lowest common multiple (LCM) of 20 and 70?

    20 · 70 · Lowest common multiple (LCM)

  5. 5. What is the lowest common multiple (LCM) of 18 and 63?

    18 · 63 · Lowest common multiple (LCM)

  6. 6. What is the lowest common multiple (LCM) of 30 and 42?

    30 · 42 · Lowest common multiple (LCM)

  7. 7. What is the lowest common multiple (LCM) of 15 and 18?

    15 · 18 · Lowest common multiple (LCM)

  8. 8. What is the lowest common multiple (LCM) of 24 and 40?

    24 · 40 · Lowest common multiple (LCM)

  9. 9. What is the lowest common multiple (LCM) of 14 and 21?

    14 · 21 · 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 4 and 10?

    4 · 10 · Lowest common multiple (LCM)

  12. 12. What is the lowest common multiple (LCM) of 8 and 20?

    8 · 20 · Lowest common multiple (LCM)
12 questions · Seed 53 · 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 55 and 66?

    330

    The highest common factor of 55 and 66 is 11, so LCM = (55 × 66) ÷ 11 = 330.

  2. 2. What is the lowest common multiple (LCM) of 20 and 28?

    140

    The highest common factor of 20 and 28 is 4, so LCM = (20 × 28) ÷ 4 = 140.

  3. 3. What is the lowest common multiple (LCM) of 16 and 40?

    80

    The highest common factor of 16 and 40 is 8, so LCM = (16 × 40) ÷ 8 = 80.

  4. 4. What is the lowest common multiple (LCM) of 20 and 70?

    140

    The highest common factor of 20 and 70 is 10, so LCM = (20 × 70) ÷ 10 = 140.

  5. 5. What is the lowest common multiple (LCM) of 18 and 63?

    126

    The highest common factor of 18 and 63 is 9, so LCM = (18 × 63) ÷ 9 = 126.

  6. 6. What is the lowest common multiple (LCM) of 30 and 42?

    210

    The highest common factor of 30 and 42 is 6, so LCM = (30 × 42) ÷ 6 = 210.

  7. 7. What is the lowest common multiple (LCM) of 15 and 18?

    90

    The highest common factor of 15 and 18 is 3, so LCM = (15 × 18) ÷ 3 = 90.

  8. 8. What is the lowest common multiple (LCM) of 24 and 40?

    120

    The highest common factor of 24 and 40 is 8, so LCM = (24 × 40) ÷ 8 = 120.

  9. 9. What is the lowest common multiple (LCM) of 14 and 21?

    42

    The highest common factor of 14 and 21 is 7, so LCM = (14 × 21) ÷ 7 = 42.

  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 4 and 10?

    20

    The highest common factor of 4 and 10 is 2, so LCM = (4 × 10) ÷ 2 = 20.

  12. 12. What is the lowest common multiple (LCM) of 8 and 20?

    40

    The highest common factor of 8 and 20 is 4, so LCM = (8 × 20) ÷ 4 = 40.

12 questions · Seed 53 · 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 55 and 66?

    55 · 66 · Lowest common multiple (LCM)

  2. 2. What is the lowest common multiple (LCM) of 20 and 28?

    20 · 28 · Lowest common multiple (LCM)

  3. 3. What is the lowest common multiple (LCM) of 16 and 40?

    16 · 40 · Lowest common multiple (LCM)

  4. 4. What is the lowest common multiple (LCM) of 20 and 70?

    20 · 70 · Lowest common multiple (LCM)

  5. 5. What is the lowest common multiple (LCM) of 18 and 63?

    18 · 63 · Lowest common multiple (LCM)

  6. 6. What is the lowest common multiple (LCM) of 30 and 42?

    30 · 42 · Lowest common multiple (LCM)

  7. 7. What is the lowest common multiple (LCM) of 15 and 18?

    15 · 18 · Lowest common multiple (LCM)

  8. 8. What is the lowest common multiple (LCM) of 24 and 40?

    24 · 40 · Lowest common multiple (LCM)

  9. 9. What is the lowest common multiple (LCM) of 14 and 21?

    14 · 21 · 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 4 and 10?

    4 · 10 · Lowest common multiple (LCM)

  12. 12. What is the lowest common multiple (LCM) of 8 and 20?

    8 · 20 · Lowest common multiple (LCM)
12 questions · Seed 53 · 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 55 and 66?

    330

    The highest common factor of 55 and 66 is 11, so LCM = (55 × 66) ÷ 11 = 330.

  2. 2. What is the lowest common multiple (LCM) of 20 and 28?

    140

    The highest common factor of 20 and 28 is 4, so LCM = (20 × 28) ÷ 4 = 140.

  3. 3. What is the lowest common multiple (LCM) of 16 and 40?

    80

    The highest common factor of 16 and 40 is 8, so LCM = (16 × 40) ÷ 8 = 80.

  4. 4. What is the lowest common multiple (LCM) of 20 and 70?

    140

    The highest common factor of 20 and 70 is 10, so LCM = (20 × 70) ÷ 10 = 140.

  5. 5. What is the lowest common multiple (LCM) of 18 and 63?

    126

    The highest common factor of 18 and 63 is 9, so LCM = (18 × 63) ÷ 9 = 126.

  6. 6. What is the lowest common multiple (LCM) of 30 and 42?

    210

    The highest common factor of 30 and 42 is 6, so LCM = (30 × 42) ÷ 6 = 210.

  7. 7. What is the lowest common multiple (LCM) of 15 and 18?

    90

    The highest common factor of 15 and 18 is 3, so LCM = (15 × 18) ÷ 3 = 90.

  8. 8. What is the lowest common multiple (LCM) of 24 and 40?

    120

    The highest common factor of 24 and 40 is 8, so LCM = (24 × 40) ÷ 8 = 120.

  9. 9. What is the lowest common multiple (LCM) of 14 and 21?

    42

    The highest common factor of 14 and 21 is 7, so LCM = (14 × 21) ÷ 7 = 42.

  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 4 and 10?

    20

    The highest common factor of 4 and 10 is 2, so LCM = (4 × 10) ÷ 2 = 20.

  12. 12. What is the lowest common multiple (LCM) of 8 and 20?

    40

    The highest common factor of 8 and 20 is 4, so LCM = (8 × 20) ÷ 4 = 40.

12 questions · Seed 53 · Age guidance, not curriculum certification