Listing what divides a number evenly (its factors) and what it divides into evenly (its multiples), then finding what two numbers share.
Example: Factors of 12: 1, 2, 3, 4, 6, 12
Find Factors and Multiples
I can find the greatest common factor and the least common multiple of two numbers, and use each to solve a real problem.
Speaking and writing goal: I can explain my choice using the words factor, multiple, common, greatest, and least.
What Your Child Is Learning
In this lesson, students practice how to find the greatest common factor and the least common multiple of two numbers, and use each to solve a real problem. They learn to show their thinking with numbers, pictures, words, or a model. The goal is not just getting an answer. Students should be able to explain why the answer makes sense.
Why This Matters
This skill supports everyday problem solving with money, measurements, games, planning, and checking whether an answer is reasonable.
What It May Look Like In Class
Your child may use the interactive lesson, guided notes, examples from the board, partner talk, and short practice problems. They may be asked to solve, draw a model, label important numbers, and explain their reasoning in a sentence.
How You Can Help At Home
You do not need to teach a new method. Ask your child to read the problem out loud, circle the important numbers, and explain what they tried first. Helpful questions include: What do you know? What are you trying to find? Does your answer make sense?
Apoyo para familias en español
Qué está aprendiendo su hijo/a
En esta lección, su hijo/a practica usar números con cuidado y explicar sus pasos. Puede usar dibujos, números, palabras o modelos para mostrar su pensamiento. Lo más importante es que pueda explicar por qué su respuesta tiene sentido.
Por qué es importante
Esta habilidad ayuda con dinero, medidas, juegos, planificación y con revisar si una respuesta es razonable.
Cómo puede ayudar en casa
No necesita ser experto/a en matemáticas. Pídale a su hijo/a que lea el problema en voz alta, marque los números importantes y explique su primer paso. Puede preguntar: ¿Qué sabes? ¿Qué necesitas encontrar? ¿Tu respuesta tiene sentido?
Key Vocabulary
A whole number that divides another number evenly, with no remainder.
Example: 4 dividing 12 exactly
The result of multiplying a number by 1, 2, 3, and so on — where you land when you skip-count by it.
Example: 24 as a multiple of 8
The largest number that is a factor of two or more numbers. It answers “how many equal groups can I make?”
Example: 6 for 12 and 18
The smallest number that is a multiple of two or more numbers. It answers “when will these line up again?”
Example: 12 for 4 and 6
Two factors that multiply to make a number. In a word problem, one is the number of groups and the other is the size of each group.
Example: 4 and 9 for 36
Try It Together
Pick one or two problems. Let your child explain the first step before opening the answer.
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Make a factor tree for 36.
Show answer
36 = 2 x 2 x 3 x 3
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List all factors of 24.
Show answer
1, 2, 3, 4, 6, 8, 12, 24
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Is 29 prime or composite? How do you know?
Show answer
Prime; only 1 and 29 divide it evenly.
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What is the greatest common factor of 18 and 30?
Show answer
6