 # Wednesday, October 20 (Blue) Thursday, October 21 (Gold) Objective Students add and subtract fractions and mixed numbers Fill in planner Today’s Assignment.

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Wednesday, October 20 (Blue) Thursday, October 21 (Gold) Objective Students add and subtract fractions and mixed numbers Fill in planner Today’s Assignment (Practice 5-3) Bell Work Compare the fractions using, or =

Adding Fractions with different denominators Problem: You can’t add fractions with different denominators. Solution: Turn fractions into equivalent fractions with a common denominator, preferably the LCD!

Finding the Lowest Common Denominator The lowest common multiple of two numbers is the lowest number in BOTH lists of multiples Multiples of 2 are 2, 4, 6, 8, 10…… Multiples of 3 are 3, 6, 9, 12, ……… What is the lowest common multiple? Example 1

Finding the Lowest Common Denominator The lowest common multiple of two numbers is the lowest number they will BOTH divide into 2 divides into 2, 4, 6, 8….. 3 divides into 3, 6, 9…. What is the lowest number 2 and 3 both divide into?

+ The Lowest Common Multiple of 2 and 3 is 6 so turn all fractions into sixths You can’t add fractions with different denominators Special form of 1

Lowest common denominator is 10 so make all fractions tenths Example 2

Turn both fractions into twelfths Example 3:

Variable Expressions Example 4

Variable Expressions Example 5

Variable Expressions Example 6

Adding Mixed Numbers Find the sum. 1 4949 + 3 1919 1.Rewrite the fraction using LCD if denominators are different. 2. Add or subtract the fractions, then the whole numbers. 3. Simplify if possible. 4 5959 In this problem, the denominators are the same, so begin with step 2.

Let’s Do More Examples! 1 4949 3 1313 + = 9 3 X 3 4 7979 4 7878 5 1414 + = 8 2 X 2 9 9898 = 1 1818 10 1818 Add the whole numbers. Example 8 Example 9

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