1. Simplifying Fractions
Lesson 5-2

2. Divisibility Rules
A whole number is divisible by: -2 if the ones digit is divisible by 2 (ends in 2, 4, 6, 8, or 0 -3 if the sum of the digits is divisible by 3 -4 if the number formed by the last two digits is divisible by 4 -5 if the ones digit is 5 or 0 -6 if the number is divisible by both 2 and 3 -9 if the sum of the digits is divisible by if the ones digit is 0

3. Replace the  with a number in so the fractions are equivalent.
multiply the numerator and denominator by 4.
Example 2-1a

4. Replace the  with a number in so the fractions are equivalent.
Example 2-1b

5. Replace the  with a number in so the fractions are equivalent.
divide the numerator and denominator by 8.
Example 2-2a

6. Replace the  with a number in so the fractions are equivalent.
Example 2-2b

7. Divide by common factors.
Write in simplest form.
Method 1
Divide by common factors.
2 is a common factor of 14 and 42.
7 is a common factor of 7 and 21.
Example 2-3a

8. factors of 14: 1, 2, 7, 14 factors of 42: 1, 2, 3, 6, 7, 14, 21, 42
Method 2
Divide by the GCF.
factors of 14: 1, 2, 7, 14 factors of 42: 1, 2, 3, 6, 7, 14, 21, 42
The GCF of 14 and 42 is 14.
Divide the numerator and denominator by the GCF, 14.
Answer: Since the GCF of 1 and 3 is 1, the fraction is in simplest form.
Example 2-3b

9. Write in simplest form.
Example 2-3c

10. Divide the numerator and denominator by the GCF, 8.
GYMNASTICS Lin practices gymnastics 16 hours each week. There are 168 hours in a week. Express the fraction in simplest form.
Divide the numerator and denominator by the GCF, 8.
Example 2-4a

11. TRANSPORTATION There are 244 students at Longfellow Elementary School
TRANSPORTATION There are 244 students at Longfellow Elementary School. Of those students, 168 ride a school bus to get to school. Express the fraction in simplest form.
Answer:
Example 2-4b