2 24 Adding & Subtracting Fractions With Unlike Denominators

04/10/2023 Bitsy Griffin Lessons 2-24 & 25

1

Adding & Subtracting Fractions with unlike

denominators12/8/09EQ: How do I add & subtract fractions when the denominator is different?


2

Review:•How do you add fractions with the same denominator?


3

Problem 1:•Eleni ate ¼ box of cereal.

•Freddie ate 3/8 box of the same box of cereal.


4

Problem 1:•What portion of the box did they eat in all?


5

Problem 1:•What needs to happen to add these 2 fractions?

•Need same denominator.


6

Problem 1:•Need same denominator.

•Least Common Denominator

•LCD


7

Problem 1:•How can we get the same denominator?

•¼ =•2/8


8

Problem 1:•2/8 + 3/8 = 5/8•Can it be simplified?


9

Problem 1:•How much more did Freddie eat?

•3/8 - 2/8 = 1/8•Can it be simplified?


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Problem 2:•How would we solve:•¼ + 2/3•Common denominator is?

•12


11

Problem 2:•¼ = ?/12 •3/12•2/3 = ?/12•8/12


12

Problem 2:•3/12 + 8/12 =•11/12•Can it be simplified?


13

Problem 2:•3/12 + 8/12 =•11/12•Can it be simplified?


14

Problem 3:•Rosa bought 4/6 yd of copper pipe.

•She used ½ yd to repair the shower.


15

Problem 3:•How much pipe does she have left?

•Set up problem.


16

Problem 3:•4/6 – ½ =•What do we need to do?


17

Problem 3:•½ = ?/6•3/6•4/6 – 3/6 = •1/6•Can it be simplified?


18

Problem 3:•¾ - 1/3 =•What is the LCD?•12


19

Problem 3:•¾ = ?/12•9/12•1/3 = ?/12•4/12


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Problem 3:•9/12 - 4/12=•5/12•Can it be simplified?


21

EQ:•How do I add & subtract fractions when the denominator is different?

Education

2 24 Adding & Subtracting Fractions With Unlike Denominators