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Unit 2: Multiplying Fractions
Remember that fractions are parts of a whole or a part of a set of objects. For example, if a bag of apples contains 10 apples and three of the apples are used to make apple tarts, three-tenths, 3/10, of the apples have been used and seven-tenths, 7/10, of the original set of 10 apples remain. Often it is necessary to take a part of a part . For example, if a recipe for cake that will serve 4 people requires three-fourths, ¾, cup of flour, adjustments to the recipe will have to be made to make a cake that will serve 2 people. Since 2 is one-half, ½, of 4, half of the required amount of flour used to make a 4 serving cake could be used to make a cake that would serve 2 people. How can we determine the correct amount of flour to use? We need half of three-fourths, ¾, cup of flour to make a cake for two.
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Unit 2: Multiplying Fractions
You will multiply fractions when you want to take a piece, segment, or part (a fraction) of another fraction. There are two to three steps for multiplying fractions. First, multiply the top numbers, the numerators. Next, multiply the bottom numbers, the denominators. The last step is to reduce the product, that is put the product in simplest terms. Sometimes the answer may not be reduced further. In that case there will only be two steps involved. Please view the video “Multiplying Fractions” (2 min and 25 s). [If the link does not take you to the Website, copy and paste the following URL into your browser: [After you view the video you will have the opportunity to practice multiplying fractions] Multiplying Fractions Designers for Learning
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Unit 2: Multiplying Fractions
Do you remember the cake problem from the beginning of this section? We still need to determine how much flour to use for the cake recipe for two people. Remember that we need to know how much is one-half, ½, of three-fourths, ¾, cup of flour. We can determine how much flour we need by multiplying the fractions. We would multiply ¾ times ½. Our multiplication problem would look like this: Do you remember the steps for multiplying fractions? First , lets multiply the numerators. 3 x 1 = 3 Next, lets multiply the denominators. 4 x 2 = 8 So, we need ⅜ (three-eigths) cup of flour for the cake recipe for two. In order to measure ⅜ cup of flour a we could draw lines on a measuring so that that cup was divided into eight equal sections. Then take three of the equal sized ⅛ sections.
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Unit 2: Check Your Knowledge
Now, you have the opportunity to practice multiplying fractions. Calculate the product of each multiplication problem below. [Use a pencil/pen and paper to answer the questions; then, click on the arrow to see the correct answers.] Multiplying Fractions: Visualizing Correct Answers 3/32 2/24 or 1/12 (simplest form) 24/48 or 1/2 (simplest form) 2/6 or 1/3 (simplest form) Designers for Learning
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Unit 2: Answers Correct Answers 3/32 2/24 or 1/12 (simplest form)
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Designers for Learning
Unit 2: Practice Click here Click here to go to a printable worksheet on multiplying fractions. [Print the worksheet. Solve the fraction multiplication problems and give the completed worksheet to your teacher] Designers for Learning
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Unit 2: Multiplying Fractions: Word Problems
Now that you know how to multiply fractions, it is time to move to solving real-world problems which involve multiplying fractions. Please view the video “Multiplying Fractions Word Problem” (3min and 38s). [If the link does not take you to the Website, copy and paste the following URL into your browser: [After you view the video move to the next slide to watch two more short videos on multiplying fractions] Multiplying Fractions Word Problem Use this type of slide for a link to a video with directions on what students should do. Designers for Learning
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Unit 2: Multiplying Fractions: Word Problems
The following videos provide additional examples of how to use your knowledge of how to multiply fractions to provide answers to questions you might have in everyday life.. Please view the video “Multiplying Fractions Word Problems (ex 1)” (2min and 12s) and the video ”Multiplying Fractions Word Problem 4” (1 min and 19s). [If the link does not take you to the Website, copy and paste the following URL into your browser: [After you view the videos you will have the opportunity to practice solving word problems using multiplication of fractions]] Multiplying Fractions Word Problem (ex 1) Multiplying Fractions Word Problem 4 Use this type of slide for a link to a video with directions on what students should do. Designers for Learning
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Unit 2: Multiplying Fractions: Word Problems
George has a piece of lumber that is 6 feet. He needs 2/3 of the lumber to use for a doorway on a tree house he is building. How much of the 6 feet piece of lumber will George use? To find out how much lumber George will use for the doorway, we must use multiplication. Often, in word problems the word “of” means multiply. We need to determine what is 2/3 (two-thirds) of six. That is 2/3 x 6. Here is our fraction multiplication problem: Here is the solution: George needs 4 feet of lumber for the doorway.
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Unit 2: Multiplying Fractions: Word Problems
Practice Taffy and Margot love a bargain. They heard that the local supermarket has whole chickens on sale for 2/3 (two-thirds) of the usual price. The supermarket usually charges 9 dollars for whole chickens. How much are the whole chickens now that they are on sale for 2/3 of the usual price? Solve the fraction multiplication word problem. Then use the next slide to check your work.
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Unit 2: Multiplying Fractions: Word Problems
Taffy and Margot need to know what is 2/3 (two-thirds) of nine dollars. They want to know if the sale on chickens is a bargain or not . To find out the sale price on the chickens, Taffy and Margot could use multiplication. They need to determine what is 2/3 (two-thirds) of nine dollars.. That is 2/3 x 9. Here is our fraction multiplication problem: Here is the solution: Taffy and Margot can buy whole chickens for only 6 dollars each. That is a bargain!
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Unit 2: Practice: Fraction Multiplication Word Problems
Click here to go to a printable worksheet on fraction multiplication word problems.. [Print the worksheet. Solve the fraction multiplication word problems and give the completed worksheet to your teacher] Designers for Learning
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Unit 2: Multiplying Fractions
How comfortable are you with multiplying fractions? Very uncomfortable Somewhat comfortable Comfortable Very Comfortable If your comfort level is 1 (very uncomfortable or 2 (somewhat comfortable) go back and review this section.
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Unit 2: Multiplying Fractions Resources
“Multiplying Fractions” 2mins25s “Multiplying fractions word problem” 3mins38s “Multiplying fractions word problems (ex 1)” 2mins12s “Multiplying fractions word problem 4” 1min19s
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Unit 3: Dividing Fractions
Dividing fractions is very similar to multiplying fractions. In fact, to solve a problem which involves dividing fractions, you will actually multiply! Please view the video How to Divide Fractions (6 min and 52 s). [If the link does not take you to the Website, copy and paste the following URL into your browser: [After you view the video you will have the opportunity to practice dividing fractions] How to Divide Fractions Designers for Learning
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Unit 3: Check Your Knowledge
Now, you have the opportunity to practice dividing fractions. Calculate the quotient of each division problem below. Remember to flip the fraction after the division sign, that is get the reciprocal. Then, multiply the two fractions. [Use a pencil/pen and paper to answer the questions; then, click on the arrow to see the correct answers.] Correct Answers 9/10 8/3 16/10 or 8/5 (simplest form) 6/5 Designers for Learning
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Unit 3: Answers Correct Answers 9/10 8/3 16/10 or 8/5 (simplest form)
6/5
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Designers for Learning
Unit 3: Practice Click here to go to a printable worksheet on dividing fractions. [Print the worksheet. Solve the fraction division problems and give the completed worksheet to your teacher] Designers for Learning
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Unit 3: Dividing Fractions: Word Problems
Now that you know how to divide fractions, it is time to move to solving real-world problems which involve dividing fractions. Please view the video “Solving Fraction Word Problems- Fraction Division” (4min and 2s). [If the link does not take you to the Website, copy and paste the following URL into your browser: ] [After you view the video move to the next slide to watch another video on dividing fractions word problems] Solving Fraction Word Problems- Fraction Division Use this type of slide for a link to a video with directions on what students should do. Designers for Learning
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Unit 3: Dividing Fractions: Word Problems
Please view the following video for more instruction on solving everyday problems by dividing fractions.. Please view the video “Dividing Fractions Word Problem” (2min and 7s). [If the link does not take you to the Website, copy and paste the following URL into your browser: [After you view the video you will have the opportunity to practice dividing fractions] Dividing Fractions Word Problem Use this type of slide for a link to a video with directions on what students should do. Designers for Learning
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Unit 3: Practice: Fraction Division Word Problems
Click here to go to a printable worksheet on fraction division word problems. [Print the worksheet. Solve the fraction division word problems and give the completed worksheet to your teacher] Designers for Learning
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Unit 3: Dividing Fractions
How comfortable are you with dividing fractions? 1………………………………………2……………………………… 3……………………………4 Very uncomfortable Somewhat comfortable Comfortable Very Comfortable If your comfort level is 1 (very uncomfortable or 2 (somewhat comfortable) go back and review this section.
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Unit 3: Dividing Fractions Resources
“How to Divide Fractions” 6mins52s “Solving Fraction Word Problems-Fraction Division” 4min2s “Dividing Fractions Word Problem” 2mins7s
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