Download Factors

Lesson 6.4
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Name
Factors
The factors of a number are the numbers that divide evenly into it.
Prime factors are the factors of a given number that are prime.
A prime number has exactly two factors, 1 and itself. A composite
number has more than two factors.
You can use division to find the factors of a number.
Find the factors of 45.
Step 1
You know that 45 is an odd number so
it cannot be divided by 2. Try dividing by 3.
45 ÷ 3 = 15
So, 3 × 15 = 45.
3 and 15 are factors of 45.
Step 2
Identify the factors as prime or composite numbers.
3 is a prime number. Its factors are 1 and itself.
15 is a composite number. It’s factors are: 1, 3, 5, and itself.
Step 3
You can divide 15 further because it is not a prime number.
15 ÷ 3 = 5
3 and 5 are prime factors.
So, the prime factors of 45 are: 3, 3, and 5
Step 4
You can write 45 as a product of its prime factors.
Write them in order from least to greatest.
3 × 3 × 5 = 45
Write the number as the product of prime factors.
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8
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15
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Grade 5