Factors, Multiples & Primes · grades 5–7

Factors, Multiples & Primes.

The building blocks of numbers — factors, multiples, primes, prime factorization with a factor tree, and the GCF and LCM. With a number grid, a factor tree, an animated step solver, and an engine-graded pad.

Factors

What divides evenly.

1.1
What is a factor?
It divides with no remainder.
1.2
Find all factors
Use factor pairs.
1.3
Divisibility rules
2, 3, 5, 9, 10.
1.4
Divisible by 4 and 6
Combine the rules.

Multiples

Skip-counting.

2.1
What is a multiple?
Skip-counting.
2.2
List multiples
Multiply by 1, 2, 3, …
2.3
Common multiples
Shared by two numbers.

Primes & prime factorization

Building blocks.

3.1
Prime vs composite
Two factors, or more.
3.2
Find the primes
The sieve.
3.3
Prime factorization
Use a factor tree.
3.4
Exponent form
2²·3² for 36.
3.5
One way only
Factorization is unique.

Greatest common factor

The biggest shared factor.

4.1
Common factors
Shared by two numbers.
4.2
GCF by listing
List factors, compare.
4.3
GCF by primes
Lowest power of shared primes.
4.4
GCF in the real world
Sharing & simplifying.

Least common multiple

The smallest shared multiple.

5.1
The least common multiple
Smallest shared multiple.
5.2
LCM by listing
List multiples, compare.
5.3
LCM by primes
Highest power of each prime.
5.4
LCM in the real world
When things line up.

Capstone

GCF or LCM?

C1
GCF or LCM?
Pick the right tool.

Factors, Multiples & Primes.

Factors

What is a factor?

Find all factors

Divisibility rules

Divisible by 4 and 6

Multiples

What is a multiple?

List multiples

Common multiples

Primes & prime factorization

Prime vs composite

Find the primes

Prime factorization

Exponent form

One way only

Greatest common factor

Common factors

GCF by listing

GCF by primes

GCF in the real world

Least common multiple

The least common multiple

LCM by listing

LCM by primes

LCM in the real world

Capstone

GCF or LCM?