8 + 8 and 4 x 4 are 2 names for the number 16. write at least 5 other names for 16.
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Vocabulary
Prime Factorization: is finding which prime numbers you need to multiply together to get the original number.
Factor string: a multiplication expression that has at least 2 factors that are greater than 1
Example: 24 is 2 x 3 x 4 and 3 x 4 x 2
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Model
Find the factor string for 7
Find the factor string for 24
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Model answers
Find the factor string for 7
There is no factor string
Find the factor string for 24
2 x 2 x 2 x 3
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Factor Tree
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Factor Tree
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Prime Factorization
Example 1
What are the prime factors of 12?
It is best to start working from the smallest prime number, which is 2, so let's check:
12 ÷ 2 = 6
But 6 is not a prime number, so we need to factor it further:
6 ÷ 2 = 3
And 3 is a prime number, so:
12 = 2 × 2 × 3
As you can see, every factoris a prime number, so the answer must be right - the prime factorization of 12 is 2 × 2 × 3, which can also be written 22 × 3
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Prime Factorization
What is the prime factorization of 147?
Can we divide 147 evenly by 2? No, so we should try the next prime number, 3:
147 ÷ 3 = 49
Then we try factoring 49, and find that 7 is the smallest prime number that works:
49 ÷ 7 = 7
And that is as far as we need to go, because all the factors are prime numbers.