Big Ideas Math: Modeling Real Life, Grade 7
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Big Ideas Math: Modeling Real Life, Grade 7 View details
1. Rational Numbers
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Exercise 7 Page 7

Find the product of the common prime factors.

7

Practice makes perfect
The greatest common factor (GCF) is the greatest number that is a factor of two or more numbers. The first step for finding a GCF is to break down each number into its prime factors. We will write down all of the prime factors that are common between the given numbers. Notice that 7 is a prime number, which means it is its own prime factorization.
Given number Prime Factorization Common Prime Factors
7 7 7
28 2* 2* 7 2, 2, 7

For the given values, the only common prime factor is 7. This means that the GCF for this pair of numbers is 7.