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Today we will be adding and subtracting fractions with LIKE denominators.

“A piece of pie!”

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How about some warm-ups?

Write each fraction in simplest form:

1. 1/4

2. 4/7

3. 1/3

4. 5/6

5. Already simplified!

10 40

12 28

8 24

20 24

7 12

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Let’s review some of the concepts of the last lesson!

Last time, we learned how to estimate the sums and differences of fractions and mixed numbers.

We used benchmarks of 0, ½, and 1 to round fractions. Our guidelines are as follows:

When numerator is much smaller than denominator round to 0 When numerator is almost half of denominator round to ½ When numerator is almost same as denominator round to 1

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To estimate sums and differences of mixed numbers, round to the nearest whole number.

If mixed number has a fraction of ½ or greater round up to next whole number.

If mixed number has a fraction less than ½ leave whole number the same!

Very Well….Lets carry on to today’s lesson

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To add with like denominators, we can follow three simple steps:

1. Add the numerator.

2. Keep the denominator the same.

3. If we need to….Simplify!!

4 + 2 = 4 + 2 = 6 7 7 7 7

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At a bake sale, of a cherry pie and of an apple pie are sold. What is the total amount of pie sold?

• In this problem we are asked to find the sum of

• Our first step is to add the numerator.

• Second step is to keep the denominator the same.

• In this case the fraction is already simplified.

4 + 7 12 12

4 + 7 = 4 + 7 = 11 12 12

12 12

4 12

7 12

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Your Turn

• Marie set out to bake a lemon meringue pie. The depth of a pie pan that she used is cm deep. After baking, the crust rises another cm above the pan. How deep is Marie’s pie? 1/3

1 6

1 6

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Sometimes, the sum of fractions is greater than 1. In this case we must rename the improper fraction, as a mixed

number.

• After the thanksgiving day dinner, of a pecan pie and of a pumpkin pie were left. What fractions of the pies remain?

Combine numerators over denominators.

Add the numerators.

Denominators remain the same.

1 Write as a mixed number.

1 Simplify.

7 + 5 = 7 + 5 9 9 9

12 9

3 9

1 3

7 9

5 9

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You try this one!

• A mix fruit pie recipe calls for cups of apples, and cups of cherries. What is the total amount of fruit that the recipe requires?

1 1/4

3 8

7 8

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Just like adding fractions with like denominators, we can also subtract with like denominators following

3 simple steps:

1. Subtract the numerator.

2. Keep the denominator the same.

3. If we need to….Simplify!!

4 _ 2 = 4 - 2 = 2 7 7 7 7

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A pie is cut into eight equal pieces. Six slices are topped with cherries. The two remaining pieces are topped with walnuts. How

much more of the pie is topped with cherries than walnuts?

• We are asked to find the difference between

First subtract the numerators.

Denominators remain the same.

Write the fraction in simplest form.

6 2 8 8

6 2 = 6 - 2 8 8 8

4 8

1 2

Combine numerators over denominators.

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You try this one!

7. A caterer orders 105 pies. The order includes 50 apple pies, 30 peach pies, and some cherry pies. What fraction of the pies are cherry pies? 5/21

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Let’s take a break!

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Unscramble each of the clue words. Copy the letters in the numberedcells to other cells with the same number.

Today’s lesson is ……………..

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Answers

1. NUMERATOR

2. DENOMINATOR

3. BENCHMARK

4. ESTIMATE

5. SUM

6. DIFFERENCE

Today’s lesson is A PIECE OF PIE.

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Assessment

1. Greg, otherwise known as the “left-over-eater- upper,” is getting ready to get his hands on the remains from the party. ¼ of the apple pie and and ¼ of the cherry pie are left over. What are the steps by which we can find the sum of the leftover pies that Greg will eat? Add numerator. Denominator stay the same.

2. Add 2/3

3. Add 1 1/2

4. Subtract 5/8

2 + 4 9 9

3 + 3 4 4

7 1 8 8

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5. Find 9 + 2 11 6/7

6. Replace x to make the equation true. 5

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4 14

7 _ x = 1 12 12 6

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8. At Mario’s bakery, of the customers purchased banana nut pie, . of the customers purchased apricot pie, and of the customers purchased kiwi lime pie.

(a) What portion of the customers purchased either banana nut or apricot pie? 2/5

(b) What is the difference in fractions between the customers who purchased kiwi pie and apricot pie? 1/10

(b) What portion of the customers purchased another type of pie? 7/20

5 20 3

20 5 20

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Lets recap what we learned today!

Today we learned how to add and subtract fractions with like denominators.

To add fractions with like denominators, we add the numerator, and keep the denominator the same!

Sometimes, our sum is greater than 1. In this case, we rename the improper fraction into a mixed number.

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To subtract fractions with like denominators, we first subtract the numerator, and leave the denominator the same.

Always remember to simplify, when needed!

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You did an excellent job today!

…….Care for some pie?