Dividing Fractions Objective Divide Whole Numbers and Unit

Dividing Fractions Objective: Divide Whole Numbers and Unit Fractions Divide Unit Fractions by Whole Numbers

Let’s Start with some Basics - What is a Unit Fraction? - What is the Reciprocal?

What is a Unit Fraction? A Unit Fraction is a Fraction that has a Numerator of 1 Examples: 1/3 1/7 1/12

What is a Reciprocal? The reciprocal of a number is: 1 divided by the number Examples: • the reciprocal of 2 is 1/2 (half) • the reciprocal of 10 is 1/10 (=0. 1) Another name for Reciprocal: Multiplicative Inverse What you multiply by a number to get 1 Example: 8 × (1/8) = 1 In other words: when we multiply a number by its "Multiplicative Inverse" we get 1.

Writing a Reciprocal Write the reciprocal of each number. a. 9 9 1 9= so the reciprocal is 1 9 7 8 b. = 8 7 3 4 c. = 4 3 7 1 = d. 7 so the reciprocal is 1 7

Dividing a Whole Number by a Unit Fraction Example: 5 ÷ 1/2 Standard Algorithm: Keep- Flip-Change (KFC Method) Keep: Keep the 1 st Fraction exactly the same NOTE: Remember, to write a Whole Number as a Fraction, put a 1 as the denominator 5/1 Flip: Flip the sign from Division to Multiplication 5/1 x ____ Change: Change the 2 nd Fraction by finding it’s reciprocal 5/1 x 2/1= Now, Solve

Suppose you have three large pizzas and you want to divide them into eighths. How many pieces would you have? This model helps us see how we can divide a whole number by a fraction. Each circle is divided into eights. You have 24 pieces. So, 3 ÷ 1/8 = 24 pieces.

To divide a fraction, multiply by the reciprocal of the fraction. You can remember this by thinking “invert and multiply. ” OR ♫ "Dividing fractions, as easy as pie, Flip the second fraction, then multiply. And don't forget to simplify, Before it's time to say goodbye" ♫

Let’s Practice

Dividing a Unit Fraction by a Whole Number Example: 1/5 ÷ 4 Keep: Keep the 1 st Fraction the same 1/5 ÷ 4= Flip: Flip the sign from Division to Multiplication 1/5 x 4… Change: Change the 2 nd fraction / Find the Reciprocal 1/5 x ¼= Solve: Solve the problem 1/5 x ¼= 1/20

Your turn…. Solve the following problems in your math notebook 1/3 ÷ 2= 6 ÷ 1/7= 1/9 ÷ 3= 10 ÷ 1/8=

You will be given a set of problems now to solve with an Elbow Partner Take your time. Use your notes. Work carefully In 10 minutes, we will go over these problems