Add Fractions with UNLIKE denominators!

Five Apples

Five Orpples? Five Fruit

“Fruit” is what they have in common!

What does 3 and 4 have in common? 12

What do they have in common?

Let’s see if you can remember some of this from last year…. Most of you got very confused last year when your teacher tried to teach you how to add fractions!

Your teacher told you... “You can use any common denominator or the least common denominator to add and subtract unlike fractions. The least common denominator (LCD) is the least common multiple of the denominators.”

And you said… Uh?

Warm Up 9 34 = 12 The L.C.M of 3 & 4 is 12 - the LCD! Page 8 in your notes! 23 8 + = 12 17 5 12 = 1 12

The Pacific Ocean covers of Earth’s surface. The Atlantic 1 3 __ The Pacific Ocean covers of Earth’s surface. The Atlantic Ocean covers of Earth’s surface. find the fraction of the Earth’s surface that is covered by both oceans: 1 5 __

Fractions that represent the same value are equivalent. To add or subtract unlike fractions, first rewrite them as equivalent fractions with a common denominator. Remember! Fractions that represent the same value are equivalent.

9 15 = 45 The L.C.M of 5 & 9 is 45 - the LCD! 79 35 + = 45 44 45

14 23 = 21 The L.C.M of 3 & 7 is 21 - the LCD! 57 15 + = 21 29 8 21 = 1 21

12 35 = 20 The L.C.M of 5 & 4 is 20 - the LCD! 14 5 - = 20 7 20

4 15 = 20 The L.C.M of 5 & 4 is 20 - the LCD! 34 15 + = 20 19 20