Decimal Multiplication

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Decimal Multiplication · Grade 5 · Worksheet 3

1. Emma is making friendship bracelets for her classmates. Each bracelet requires 0.35 meters of colorful yarn. If she needs to make bracelets for 12 classmates, how many meters of yarn does Emma need in total? Answer: 4.2 Solution: Each bracelet requires 0.35 meters of yarn Emma needs to make 12 bracelets Multiply the length per bracelet by the number of bracelets: 0.35 × 12 First multiply 35 × 12 = 420 Since 0.35 has two decimal places, move the decimal point two places to the left: 420 becomes 4.20 4.20 is the same as…
   Full step-by-step solution

   Step 1: Each bracelet requires 0.35 meters of yarn Step 2: Emma needs to make 12 bracelets Step 3: Multiply the length per bracelet by the number of bracelets: 0.35 × 12 Step 4: First multiply 35 × 12 = 420 Step 5: Since 0.35 has two decimal places, move the decimal point two places to the left: 420 becomes 4.20 Step 6: 4.20 is the same as 4.2 The answer is 4.2 meters.

2. Mere is drawing a rectangular sandpit on a coordinate grid. The corners are at (2, 3), (10, 3), (10, 7.25), and (2, 7.25). Each unit on the grid represents 1 meter. What is the area of the sandpit in square meters? Answer: 34 Solution: Find the length by subtracting the x-coordinates of the left and right corners: 10 - 2 = 8 meters. Find the width by subtracting the y-coordinates of the bottom and top corners: 7.25 - 3 = 4.25 meters.
   Full step-by-step solution

   Step 1: Find the length by subtracting the x-coordinates of the left and right corners: 10 - 2 = 8 meters. Step 2: Find the width by subtracting the y-coordinates of the bottom and top corners: 7.25 - 3 = 4.25 meters. Step 3: Multiply the length by the width to find the area: 8 × 4.25. Step 4: Break 4.25 into 4 + 0.25. 8 × 4 = 32, and 8 × 0.25 = 2. Then 32 + 2 = 34. Step 5: The area of the sandpit is 34 square meters. The answer is 34.

3. Liam is building a wooden bookshelf and needs to cut 4 identical shelves from a long board. Each shelf needs to be 1.75 meters long. How many meters of board does Liam need in total for the 4 shelves? Answer: 7 Solution: We are told that Liam needs 4 identical shelves, each 1.75 meters long. We need the total length of board required for all 4 shelves. That means we multiply the length of one shelf by the number of shelves.
   Full step-by-step solution

   We are told that Liam needs 4 identical shelves, each 1.75 meters long. Step 1: Understand the problem We need the total length of board required for all 4 shelves. That means we multiply the length of one shelf by the number of shelves. Step 2: Write the multiplication Total length = 4 × 1.75 Step 3: Break down the multiplication 1.75 is the same as 1 + 0.75 So 4 × 1.75 = 4 × (1 + 0.75) Step 4: Multiply each part 4 × 1 = 4 4 × 0.75 = 4 × (3/4) = 12/4 = 3 Step 5: Add the results 4 + 3 = 7 Step 6: Conclusion Liam needs 7 meters of board in total. Answer: 7

4. 9.28 × 47 = ? Answer: 436.16 Solution: Multiply 9.28 by 47 as if they were whole numbers: 928 × 47 928 × 40 = 37,120 928 × 7 = 6,496 Add the partial products: 37,120 + 6,496 = 43,616 Since 9.28 has two decimal places, the product must also have two decimal places Place the decimal point two places from the right: 436.16 The answer is…
   Full step-by-step solution

   Step 1: Multiply 9.28 by 47 as if they were whole numbers: 928 × 47 Step 2: 928 × 40 = 37,120 Step 3: 928 × 7 = 6,496 Step 4: Add the partial products: 37,120 + 6,496 = 43,616 Step 5: Since 9.28 has two decimal places, the product must also have two decimal places Step 6: Place the decimal point two places from the right: 436.16 The answer is 436.16.

5. 4.25 × 12 = ? Answer: 51 Solution: Write the multiplication: 4.25 × 12 Multiply 4.25 by 10: 4.25 × 10 = 42.5 Multiply 4.25 by 2: 4.25 × 2 = 8.5 Add the two results: 42.5 + 8.5 = 51 The answer is 51.
   Full step-by-step solution

   Step 1: Write the multiplication: 4.25 × 12 Step 2: Multiply 4.25 by 10: 4.25 × 10 = 42.5 Step 3: Multiply 4.25 by 2: 4.25 × 2 = 8.5 Step 4: Add the two results: 42.5 + 8.5 = 51 Step 5: The answer is 51.

6. Maria is baking cookies for a school fundraiser. Each batch requires 0.375 kilograms of flour. If she plans to bake 12 batches of cookies, how many kilograms of flour does Maria need in total? Answer: 4.5 Solution: Identify the amount of flour needed for one batch: 0.375 kg Identify the number of batches: 12 Multiply to find the total flour needed: 0.375 × 12 Calculate: 0.375 × 12 = 4.5 Maria needs 4.5 kilograms of flour in total.
   Full step-by-step solution

   Step 1: Identify the amount of flour needed for one batch: 0.375 kg Step 2: Identify the number of batches: 12 Step 3: Multiply to find the total flour needed: 0.375 × 12 Step 4: Calculate: 0.375 × 12 = 4.5 Maria needs 4.5 kilograms of flour in total.

7. Olivia is buying 12 packs of stickers for a school project. Each pack costs $1 dollars. How much will Olivia spend in total? Answer: 12 Solution: Identify the number of packs: 12 packs. Identify the cost per pack: $1 per pack. Multiply to find the total: 12 × 1 = 12.
   Full step-by-step solution

   Step 1: Identify the number of packs: 12 packs. Step 2: Identify the cost per pack: $1 per pack. Step 3: Multiply to find the total: 12 × 1 = 12. The total cost is $12.

8. Isabella is selling cookies to raise money. Each box of cookies costs $1 dollars, and Isabella sells 6 boxes. How much money did Isabella raise? Answer: 6 Solution: Number of boxes sold: 6 boxes. Price per box: $1. Total money raised: 6 × 1 = 6.
   Full step-by-step solution

   Step 1: Number of boxes sold: 6 boxes. Step 2: Price per box: $1. Step 3: Total money raised: 6 × 1 = 6. Isabella raised $6.

9. 8.63 × 42 = ? Answer: 362.46 Solution: Multiply 8.63 × 42 as if they were whole numbers: 863 × 42 863 × 40 = 34,520 863 × 2 = 1,726 Add the partial products: 34,520 + 1,726 = 36,246 Since 8.63 has two decimal places, the product must also have two decimal places Place the decimal point two places from the right: 362.46 The answer is…
   Full step-by-step solution

   Step 1: Multiply 8.63 × 42 as if they were whole numbers: 863 × 42 Step 2: 863 × 40 = 34,520 Step 3: 863 × 2 = 1,726 Step 4: Add the partial products: 34,520 + 1,726 = 36,246 Step 5: Since 8.63 has two decimal places, the product must also have two decimal places Step 6: Place the decimal point two places from the right: 362.46 The answer is 362.46.