Unit 5operations With Fractionswelcome



Operations with fractions examples

Decompose a fraction (x/y) into a sum of unit parts (1/y) using visual models.Visit: to see all videos and a complete set of resourc. Unit Five Part 2: Videos. Video 1: One-Step Equations. Video 3: Distributive Property Equations.

To add (or subtract) two fractions :

1) Find the least common denominator .

2) Write both original fractions as equivalent fractions with the least common denominator.

3) Add (or subtract) the numerators.

4) Write the result with the denominator.

Example 1:

Add 1 3 + 3 7 .

The least common denominator is 21 .

Unit 5operations With Fractionswelcome

1 3 + 3 7 = 1 7 3 7 + 3 3 7 3 = 7 21 + 9 21 = 16 21

To multiply two fractions:

1) Multiply the numerator by the numerator.

2) Multiply the denominator by the denominator.

For all real numbers a , b , c , d ( b 0 , d 0 )

a b c d = a c b d

Example 2:

Multiply 1 4 5 6 .

1 4 5 6 = 1 5 4 6 = 5 24

To divide by a fraction, multiply by its reciprocal .

For all real numbers a , b , c , d ( b 0 , c , d 0 )

a b ÷ c d = a b d c = a d b c

Example 3:

Divide 3 4 ÷ 5 7 .

3 4 ÷ 5 7 = 3 4 7 5 = 3 7 4 5 = 21 20

Mixed numbers can be written as an improper fraction and an improper fraction can be written as a mixed number.

Example 4:

Write 7 2 5 as an improper fraction.

7 2 5 = 7 1 + 2 5 = 7 5 1 5 + 2 5 = 35 5 + 2 5 = 37 5

Example 5:

Order Of Operations With Fractions

Write 11 7 as a mixed number in simple form.

11 7 = 11 ÷ 7 = 1 R 4

Therefore, 11 7 = 1 4 7 .

A fraction is in lowest terms when the numerator and denominator have no common factor other than 1 . To write a fraction in lowest terms, divide the numerator and denominator by the greatest common factor .

Example 6:

Write 45 75 in lowest terms.

45 and 75 have a common factor of 15 .

Operations With Fractions Worksheets

45 75 = 45 ÷ 15 75 ÷ 15 = 3 5