# Solving Problems Involving Multiplication of Fractions.pptx

28. May 2023
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### Solving Problems Involving Multiplication of Fractions.pptx

• 1. MATHEMATICS 5 Solving Problems Involving Multiplication of Fractions Multiplying a Fraction by its Reciprocal WEEK 7
• 2. -Solve routine or non-routine problems involving multiplication without or with addition or subtraction of fractions and whole numbers using appropriate problem solving strategies and tools -Show that multiplying a fraction by its reciprocal is equal to 1. (MELC-Math 5)
• 3. What is the sum of 3 𝟒 𝟓 and 𝟏 𝟒 ? 3 𝟒 𝟓 + 𝟏 𝟒 = 𝟑 + 𝟐𝟎 + 𝟐𝟎 16 5 = 𝟑 + 𝟐𝟏 𝟐𝟎 = 𝟑 + 𝟏 𝟏 𝟐𝟎 = 𝟒 𝟏 𝟐𝟎
• 4. Butterfly or Cross-Multiplication Method =7 𝟏𝟐 2 𝟏𝟐 - =5 8 3 𝟓 𝟏𝟐
• 5. = 2 3 3 8 x 6 24 2 3 𝑜𝑓 3 8 Multiplying Fractions = = 𝟏 𝟒 Cancellation Method 1. Look for a pair of numerator and denominator to cancel or reduce. 2. Multiply. 2 3 3 8 x = 1 1 𝟏 𝟒 1 4
• 6. There was 𝟓 𝟖 of a pie left in the fridge. Liam ate 𝟏 𝟓 of the leftover pie. How much of a pie did he eat? The FOUR STEPS in Solving Problems: 1. Understand 2. Plan 3. Solve 4. Check 1. Study 2. Think 3. Act 4. Review
• 7. There was 𝟓 𝟖 of a pie left in the fridge. Liam ate 𝟏 𝟓 of the leftover pie. How much of a pie did he eat? UNDERSTAND 1. What is asked in the problem? The amount of pie Liam ate. 2. What are given? 𝟓 𝟖 of a pie left 𝟏 𝟓 of the leftover pie
• 8. There was 𝟓 𝟖 of a pie left in the fridge. Liam ate 𝟏 𝟓 of the leftover pie. How much of a pie did he eat? PLAN 1. What is the operation will be used? Multiplication 2. What is the mathematical sentence? 𝟏 𝟓 x 𝟓 𝟖 = N
• 9. There was 𝟓 𝟖 of a pie left in the fridge. Liam ate 𝟏 𝟓 of the leftover pie. How much of a pie did he eat? SOLVE 𝟏 𝟓 x 𝟓 𝟖 = N 𝟏 𝟓 x 𝟓 𝟖 = 𝟓 𝟒𝟎 = 𝟏 𝟖 Answer: Liam ate 𝟏 𝟖 of the pie.
• 10. There was 𝟓 𝟖 of a pie left in the fridge. Liam ate 𝟏 𝟓 of the leftover pie. How much of a pie did he eat? CHECK 𝟏 𝟓 x 𝟓 𝟖 = 𝟏 𝟖 Answer: Liam ate 𝟏 𝟖 of the pie. 1 1
• 11. UNDERSTAND 1. What is asked in the problem? The weight in pound of each box of cupcakes. 2. What are given? 24 cupcakes Each cupcake is 𝟐 𝟏𝟓 pound. 6 cupcakes in each box Pam baked some cupcakes for her friends. She baked 24 cupcakes. Each cupcake is 𝟐 𝟏𝟓 pound. If she packed 6 cupcakes in each box, what is the weight in pounds of each box?
• 12. Pam baked some cupcakes for her friends. She baked 24 cupcakes. Each cupcake is 𝟐 𝟏𝟓 pound. If she packed 6 cupcakes in each box, what is the weight in pounds of each box? PLAN 1. What is the operation will be used? Multiplication 2. What is the mathematical sentence? 𝟐 𝟏𝟓 x 6= N
• 13. Pam baked some cupcakes for her friends. She baked 24 cupcakes. Each cupcake is 𝟐 𝟏𝟓 pound. If she packed 6 cupcakes in each box, what is the weight in pounds of each box? SOLVE 𝟐 𝟏𝟓 x 6= N 𝟐 𝟏𝟓 x 𝟔 𝟏 = 𝟏𝟐 𝟏𝟓 = 𝟒 𝟓 Answer: The weight of each box of cupcakes is 𝟒 𝟓 pound.
• 14. CHECK 𝟐 𝟏𝟓 x 𝟔 𝟏 = 𝟒 𝟓 Answer: The weight of each box of cupcakes is 𝟒 𝟓 pound. 2 5 Pam baked some cupcakes for her friends. She baked 24 cupcakes. Each cupcake is 𝟐 𝟏𝟓 pound. If she packed 6 cupcakes in each box, what is the weight in pounds of each box?
• 15. Showing that Multiplying a Fraction by its Reciprocal is Equal to 1
• 16. Two fractions whose product is 1 are reciprocals of each other. Reciprocal means multiplicative inverse. Example: 3 4 x 4 3 = 1