Grade 6 Mathematics · Unit 6: Numerical and Algebraic ExpressionsStandard 6.NOS.4

Lesson 6.126.12 · Part II

Start hereWords, worked example, and sentence starters

Name Date Period

Learning target I can find the least common multiple (LCM) of two numbers by listing or comparing their multiples.

Start hereWords for this lesson

Read each word before you begin. Say it out loud.

WordWhat it meansExample
Least Common MultipleSpanish: Mínimo común múltiplo The least positive number that is a multiple of two or more numbers. Multiples of 4 and 6 first meet at 12, so LCM = 12.
MultipleSpanish: Múltiplo What you get when you multiply a number by 1, 2, 3, and so on. Multiples of 4: 4, 8, 12, 16, 20 — found by multiplying 4 × 1, 4 × 2, 4 × 3, ...
Common multipleSpanish: Múltiplo común A number that two or more numbers both go into. 12, 24, and 36 are all common multiples of both 3 and 4
Skip countingSpanish: Conteo salteado Counting by a number, like 2, 4, 6, to list its multiples. Skip count by 6: 6, 12, 18, 24, 30 — each jump adds 6
Prime factorizationSpanish: Factorización prima Writing a number as prime numbers multiplied together. It helps you find the LCM. 4 = 2 × 2, 6 = 2 × 3. LCM uses the highest power of each prime: 2² × 3 = 12

Say it and write itSentence starters

Finish each sentence out loud with a partner. Then use them in your writing.

Word bank Least Common MultipleMultipleCommon multipleSkip countingPrime factorization

Watch outA common mistake

A common mistake in Least Common Multiple is multiplying the two numbers together instead of listing multiples to find the smallest shared one. For example, for 4 and 6, a student calculates 4 × 6 = 24 and calls that the LCM, but the actual least common multiple is 12 (multiples of 4: 4, 8, 12; multiples of 6: 6, 12 — 12 is the first number that appears in both lists). This shortcut only works when the two numbers share no common factors (like 4 and 9, where the LCM really is 36 = 4 × 9); for numbers like 4 and 6 that share a factor of 2, multiplying overshoots the true LCM. Always list multiples of both numbers and pick the first one that appears in both lists.

Grade 6 Mathematics · Unit 6: Numerical and Algebraic ExpressionsStandard 6.NOS.4

Lesson 6.126.12 · Part II

Apply Day · Version ASupported practice

Mastery check☐ Exceeds☐ Meets target☐ Needs practice
Name Date Period

Learning target I can find the least common multiple (LCM) of two numbers by listing or comparing their multiples.

  1. 1Complete each step, then write the final answer.

    Find the LCM of 2 and 3.

    Show your work

    Hint Skip count by 3: 3, 6. Which one is also a multiple of 2?

    Final answer:
  2. 2Complete each step, then write the final answer.

    Find the LCM of 5 and 10.

    Show your work

    Hint Skip count by 10. Is 10 already a multiple of 5?

    Final answer:
  3. 3Complete each step, then write the final answer.

    Find the LCM of 2 and 9.

    Show your work

    Hint Skip count by 9: 9, 18. Which one is also a multiple of 2?

    Final answer:
How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help
Grade 6 Mathematics · Unit 6: Numerical and Algebraic ExpressionsStandard 6.NOS.4

Lesson 6.126.12 · Part II

Apply Day · Version BCore practice

Mastery check☐ Exceeds☐ Meets target☐ Needs practice
Name Date Period

Learning target I can find the least common multiple (LCM) of two numbers by listing or comparing their multiples.

  1. 1Complete each step, then write the final answer.

    Jay says the LCM of 6 and 9 is 54 because 6 × 9 = 54. Is he right? What is the LCM?

    Show your work
    Final answer:
  2. 2Complete each step, then write the final answer.

    Find the LCM of 12 and 18.

    Show your work
    Final answer:
  3. 3Complete each step, then write the final answer.

    Find the LCM of 5 and 6.

    Show your work
    Final answer:
How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help
Grade 6 Mathematics · Unit 6: Numerical and Algebraic ExpressionsStandard 6.NOS.4

Lesson 6.126.12 · Part II

Apply Day · ChallengeExtension

Mastery check☐ Exceeds☐ Meets target☐ Needs practice
Name Date Period

Learning target I can find the least common multiple (LCM) of two numbers by listing or comparing their multiples.

  1. 1Circle the letter of the best answer. Show how you know.

    What is the least common multiple of 6 and 8?

    1. A2
    2. B14
    3. C24
    4. D48
    Show your work
  2. 2Complete each step, then write the final answer.

    Ana says the LCM of two numbers is always their product. Test her rule with 10 and 25. What is the LCM of 10 and 25?

    Show your work
    Final answer:
  3. 3Complete each step, then write the final answer.

    Find the LCM of 9 and 15.

    Show your work
    Final answer:
How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help