Simplifying Fractions Lesson 5-2

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 9 -10 if the ones digit is 0

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

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

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

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

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

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

Write in simplest form. Example 2-3c

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

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