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Lesson 6: Creating Problems involving Multiplication with or without Addition/Subtraction of Fractions

Solve the following story problems. Then identify the different parts of a word problem.

A. Mang Jose is a carpenter. He made a table whose length and width measure

235

m by 56

m. What was the area of the plywood he needed for the table?

B. Jamillah received a certain amount of money from her mother. On the first

store, she spent 14

of her money to buy a handkerchief. Then on the next store,

she spent 13

of what remained to buy merienda and saved the rest. If she saved

P20, how much did she receive from her mother?Reflect::What is the difference of the two word problems above? What are the different parts of a word problem?

Refer to the picture below. What can you see on the picture? Can you create a story problem involving multiplication of fractions with addition or subtraction? (illustrate a woman who is mixing flour, sugar, water, and milk to bake a cake.)

Reflect: What do you want to know about creating problems involving multiplication and other operations?

Study the problem involving multiplication of mixed fractions that can be made using the given facts below.

Scenario Given Information Question/s Buying and sharing some kilos of rice to the calamity victims

534

, 256

,∧234

Ask about the number of kilos of rice.

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Carla bought a number of kilos of rice. He set aside 534

kilos for his family. Then he

packed the remaining into bags with 256

kilos each to be shared to earthquake victims. He

had 15 bags of rice and 234

kilos left. How many kilos of rice did he buy?

What information is needed to construct and answer routine

problems involving multiplication with or without addition and

subtraction of fractions?

Where is this information in the problem?

1. State a scenario that uses multiplication with addition and subtraction of fractions or whole numbers. Use keywords for multiplication, addition or subtraction.

Faizal bought a number of kilos of rice. He

set aside 534

kilos for his family. Then he

packed the remaining into bags with 256

kilos

each to be shared to earthquake victims. He

had 15 bags of rice and 234

kilos left.

2. Use related fractions as given. 534

, 256

, 234

3. Pose a question that require getting the product and sum or difference of two or more fractions or mixed fractions.

How many kilos of rice did he buy?

4. Use a strategy in solving the problem and/or number sentence.

Work backwards to know the number of kilos or rice.

234+(15 × 2

56)+5

34=N

5. Show the solution to the problem. 234+(15 × 2+15×

56)+5

34=N

234+30+ 25

2+5

34=N

30+2+5+( 34+ 50

4+ 3

4)=N

37+( 34+ 50

4+ 3

4)=N

37+( 564 )=37+14=51

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Elaborate

Explain

Evaluate

6. State the answer to the problem. Faizal bought 51 kilos of rice.

Using the given information above, what kind of scenario can you use in writing your own story problem?

Now examine again the problems you constructed under ENGAGE. Based on what you learned, how will you improve your problems? How will you make it into a non-routine problem? Talk with your seatmate about this.

Explain the following ideas about creating problems involving multiplication of fractions with/without addition or subtractions of fraction and mixed numbers. A. To create a word problem involving multiplication of fractions and mixed fractions.

1. State a scenario that uses multiplication with addition and subtraction of fractions or whole numbers.

2. Use keywords that denote multiplication, addition or subtraction.3. Pose a question that require getting the product and sum or difference of two or

more fractions or mixed fractions.4. Give a restriction or limit to make the problem become a non-routine.

B. To answer the problem involving multiplication of fractions and mixed fractions.1. Use a strategy and/or number sentence to solve the problem such as working

backwards, using a table, etc. 2. Show the complete solution to the problem.3. Write the answer to the problem in a complete sentence.

Use the situations on the pictures below to write one problem involving multiplication only and another problem involving multiplication with addition and/or subtraction. Use your calculator to compute for the answers. Show your complete solution to your problem.

1. (Picture of the fish port: the vendors are having an auction.)2. (Pictures of the farm: the farmers are harvesting their crops.)

A. Study the word problem below. Choose the letter of the best answer in each item.

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Maria bought 334

dozen of siopao for her family. When her daughter came home, she gave 13

of the siopao. After an hour, her son arrived from school and she gave 25

of the remaining

and three more. Then, she and her husband ate what was left. (put this inside a box)1. What is the scenario in the story?

A. Maria baked some siopao. C. Maria bought some siopao.B. Maria ordered some siopao. D. Maria divided some siopao equally.

2. Which is not a relevant information in this problem?

A. 13

of dozen of siopao C. 25

of the remaining

B. 334

dozen of siopao D. 13

of the siopao

3. Which of the following is unknown in the problem?A. The number of siopao Maria bought.B. The part of the siopao taken by her son.C. The part of the siopao taken by her daughter.D. The numbers of siopao taken by the daughter and son.

B. Read the following questions below. Explain which of the following can possible questions to the story problem above and which is/are not. 4. How many siopao were not eaten?5. How many siopao did the two children eat?6. How many dozen of siopao did Maria and her husband eat?

C. Create a story problem about multiplication of fractions with or without addition or subtraction using the given scenarios and information. Use the rubric in Appendix C as your guide in your answers.

7. working time, 834

hours, 13

of the work

8. harvesting fruits, 938

kg, 45

are ripe

D. Form a group of 4 or 5 members. Then create two problems using the scenarios below. Make a presentation of your work. Use the rubric in Appendix D as your guide in your answers.

9. baking or cooking a recipe10. area of a cloth

Pause & Reflect

Are you happy with the result of your evaluation? Why?What concepts are clear to you?What concepts are still not clear to you?What is the most desirable value or attitude that you have developed in this lesson?

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Extend

A. Do the following directions. 1. Talk to someone older than you at home about the amount of main commodities

your family consume every day (e.g. rice, sugar, etc.). Then create one story problem that involves multiplication of fractions and mixed fractions with addition and subtraction.

2. In which part of a word problem involving multiplication of fractions is the easiest for you to write? Why? How will you still enhance your skills in writing story problems?

3. Use a tool or strategy to solve the problem you created.

B. Answer the following questions. In which part of a word problem involving multiplication of fractions is the easiest for you to write? Why? How will you enhance your skills in writing story problems?

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