5.M.NF.1 Add and subtract fractions with unlike denominators Objective: I can subtract fractions with unlike denominators

Think back to yesterday What are the steps for adding fractions with unlike denominators Share with your team

Subtracting with unlike Denominators Subtracting uses all the steps as addition, but the last step is subtraction.

Least Common Denominator In order to subtract fractions you MUST be able to find the least common denominator (LCD)!!! LCD - The smallest multiple each denominator shares....

Find the LCD List multiples for each denominator 2, 4, 6, 8, 10, 12, 14, 16 3, 6, 9, 12, 15, 18, 21, 24, Identify the lowest multiple they share 3. SIX is the Least Common Denominator

Finding Equivalent Fractions LCD Ask yourself, “What do I do to the four to get a twelve? MULTIPLY BY 3 2 x x REMEMBER: Whatever you do to the bottom, you have to do to the top. Whatever you do to the top, you have to do to the bottom!

Wait....We’re Not Done LCD Ask yourself, “What do I do to the three to get a twelve? MULTIPLY BY 4 2 x x 4 4 x 3 3 x REMEMBER: Whatever you do to the top, you do to the bottom. Whatever you do to the bottom, you do to the top! 4 12

Let’s Review What We’ve Done Thus Far.... Find the LCD Make Equivalent Fractions Now....we’re ready to add or subtract

Let’s do it! 2 x x 4 4 x 3 3 x Are we done? SIMPLIFY, SIMPLIFY, SIMPLIFY 1616

Adding & Subtracting Fractions with unlike Denominators 1. Find the LCD 2. Create equivalent Fractions 3. Add or Subtract 4. Simplify

Let’s do a few together 7/8 - 1/3 5/6 - 1/4 10/12 - 3/4

Let’s watch add-and-subtract-fractions-with- unlike-denominators

Closure Think about what we learned today.... On your slate list the steps for subtracting fractions with unlike denominators Repeat today’s objective

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