6.12 · Part II
Supported Application · Guided Entry to Today's Problem
Least Common Multiple · Multiple
- Skip count multiples of each number starting with the larger number
- Identify the first non-zero multiple that appears in both lists
- Prime factorization method: Product of highest powers of all prime factors
- Least Common Multiple (Mínimo común múltiplo) — The least positive number that is a multiple of two or more numbers.
- Multiple (Múltiplo) — What you get when you multiply a number by 1, 2, 3, and so on.
- Common multiple (Múltiplo común) — A number that two or more numbers both go into.
- Skip counting (Conteo salteado) — Counting by a number, like 2, 4, 6, to list its multiples.
- Prime factorization (Factorización prima) — Writing a number as prime numbers multiplied together. It helps you find the LCM.
- 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.
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1 MULTIPLE CHOICE
What is the LCM of 2 and 7?
- A14
- B7
- C2
- D9
✏️ Workspace & Solution Steps -
2 MULTIPLE CHOICE
(Lesson 6.7) Which list shows all the factors of 12?
- A1, 2, 3, 4, 6, 12
- B12, 24, 36, 48
- C1, 12
- D2, 3, 4, 6
✏️ Workspace & Solution Steps -
3 MULTIPLE CHOICE
(Lesson 6.7) Which list shows the first four multiples of 8?
- A8, 16, 24, 32
- B1, 2, 4, 8
- C8, 9, 10, 11
- D2, 4, 6, 8
✏️ Workspace & Solution Steps
Writing Task: Justify why your mathematical solution is accurate and complete.
6.12 · Part II
On-Level Application · Standard Rigor
Least Common Multiple · Multiple
- Skip count multiples of each number starting with the larger number
- Identify the first non-zero multiple that appears in both lists
- Prime factorization method: Product of highest powers of all prime factors
- Least Common Multiple (Mínimo común múltiplo) — The least positive number that is a multiple of two or more numbers.
- Multiple (Múltiplo) — What you get when you multiply a number by 1, 2, 3, and so on.
- Common multiple (Múltiplo común) — A number that two or more numbers both go into.
- Skip counting (Conteo salteado) — Counting by a number, like 2, 4, 6, to list its multiples.
- Prime factorization (Factorización prima) — Writing a number as prime numbers multiplied together. It helps you find the LCM.
- 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.
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1 MULTIPLE CHOICE
Two buses leave the station at 8:00 AM. Bus A returns every 15 minutes and Bus B returns every 20 minutes. When is the next time both buses are at the station together?
- A9:00 AM (60 minutes later)
- B8:30 AM (30 minutes later)
- C8:40 AM (40 minutes later)
- D9:20 AM (80 minutes later)
✏️ Workspace & Solution Steps -
2 MULTIPLE CHOICE
One machine runs every 4 min, another every 6 min. They just ran together. In how many minutes do they run together again?
- A12
- B10
- C24
- D6
✏️ Workspace & Solution Steps -
3 MULTIPLE CHOICE
One ship docks every 8 min, another every 12 min. They just docked together. In how many minutes do they dock together again?
- A24
- B20
- C48
- D16
✏️ Workspace & Solution Steps
Writing Task: Justify why your mathematical solution is accurate and complete.
6.12 · Part II
Extension & Non-Routine Application
Least Common Multiple · Multiple
- Skip count multiples of each number starting with the larger number
- Identify the first non-zero multiple that appears in both lists
- Prime factorization method: Product of highest powers of all prime factors
- Least Common Multiple (Mínimo común múltiplo) — The least positive number that is a multiple of two or more numbers.
- Multiple (Múltiplo) — What you get when you multiply a number by 1, 2, 3, and so on.
- Common multiple (Múltiplo común) — A number that two or more numbers both go into.
- Skip counting (Conteo salteado) — Counting by a number, like 2, 4, 6, to list its multiples.
- Prime factorization (Factorización prima) — Writing a number as prime numbers multiplied together. It helps you find the LCM.
- 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.
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1 MULTIPLE CHOICE
What is the least common multiple of 6 and 8?
- A24
- B48
- C2
- D14
✏️ Workspace & Solution Steps
Writing Task: Justify why your mathematical solution is accurate and complete.