Multiply by 10s

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Multiply by 10s · Grade 3 · Worksheet 1

1. A school is organizing a field trip and needs to pack lunches. Each student will get a lunch box that contains 4 cookies. If there are 30 students going on the trip, how many cookies does the school need to pack in total? Answer: 120 Solution: Each student gets a lunch box with 4 cookies. There are 30 students. We need to find the total number of cookies.
   Full step-by-step solution

   Step 1: Understand the problem. Each student gets a lunch box with 4 cookies. There are 30 students. We need to find the total number of cookies. Step 2: Identify the operation. Since each student gets the same number of cookies, we multiply the number of students by the number of cookies per student. Step 3: Write the multiplication. Number of students = 30 Cookies per student = 4 Total cookies = 30 × 4 Step 4: Perform the calculation. 30 × 4 = 120 Step 5: State the final answer. The school needs to pack 120 cookies in total.

2. A school is organizing a field trip and needs to pack lunches. Each student will get a lunch bag that contains 4 cookies. If there are 60 students going on the trip, how many cookies does the school need to pack in total? Answer: 240 Solution: Each student gets 4 cookies. There are 60 students. We need to find the total number of cookies.
   Full step-by-step solution

   Step 1: Understand the problem. Each student gets 4 cookies. There are 60 students. We need to find the total number of cookies. Step 2: Identify the operation. Since each student gets the same number of cookies, we multiply the number of students by the number of cookies per student. Step 3: Write the multiplication. Total cookies = Number of students × Cookies per student Total cookies = 60 × 4 Step 4: Perform the calculation. 60 × 4 = 240 Step 5: State the answer. The school needs to pack 240 cookies in total.

3. A school is organizing a reading challenge. Each student who completes the challenge reads 20 books. If 45 students complete the challenge, how many books did they read in total? Answer: 900 Solution: Each student reads 20 books. There are 45 students who completed the challenge. To find the total number of books, multiply the number of books per student by the number of students: 20 × 45.
   Full step-by-step solution

   Step 1: Each student reads 20 books. Step 2: There are 45 students who completed the challenge. Step 3: To find the total number of books, multiply the number of books per student by the number of students: 20 × 45. Step 4: First, multiply 20 by 40: 20 × 40 = 800. Step 5: Then, multiply 20 by 5: 20 × 5 = 100. Step 6: Add the two results together: 800 + 100 = 900. The students read 900 books in total.

4. A bakery is preparing for a school event and needs to make cupcakes. Each box holds 30 cupcakes, and the bakery packs 80 boxes. How many cupcakes are packed in total? Answer: 2400 Solution: Identify what you know. Each box holds 30 cupcakes, and there are 80 boxes. To find the total number of cupcakes, multiply the number of cupcakes per box by the number of boxes.
   Full step-by-step solution

   Step 1: Identify what you know. Each box holds 30 cupcakes, and there are 80 boxes. Step 2: To find the total number of cupcakes, multiply the number of cupcakes per box by the number of boxes. Step 3: Calculate 30 × 80. Step 4: First, multiply 30 by 8 (which is 80 without the zero): 30 × 8 = 240. Step 5: Since we actually multiplied by 80 (which is 8 tens), we add a zero to the result: 240 becomes 2400. Step 6: Therefore, 30 × 80 = 2400. The bakery packed 2400 cupcakes in total.

5. A factory produces toy cars and packages them in boxes. Each box contains 40 toy cars. If the factory fills 70 boxes in one day, how many toy cars are produced in total? Answer: 2800 Solution: Each box contains 40 toy cars. The factory fills 70 boxes.
   Full step-by-step solution

   Step 1: Each box contains 40 toy cars. Step 2: The factory fills 70 boxes. Step 3: To find the total number of toy cars, multiply the number of cars per box by the number of boxes: 40 × 70 Step 4: First, multiply 40 by 7: 40 × 7 = 280 Step 5: Since we actually have 40 × 70, we need to multiply 280 by 10: 280 × 10 = 2800 Step 6: The factory produces 2800 toy cars in total.

6. A farmer has 24 apple trees in each row of his orchard. If there are 30 rows, how many apple trees are there in total? Answer: 720 Solution: We are told that the farmer has 24 apple trees in each row and there are 30 rows in total. To find the total number of apple trees, we multiply the number of trees per row by the number of rows.
   Full step-by-step solution

   We are told that the farmer has 24 apple trees in each row and there are 30 rows in total. To find the total number of apple trees, we multiply the number of trees per row by the number of rows. Step 1: Identify the numbers given. Trees per row = 24 Number of rows = 30 Step 2: Multiply the two numbers. Total trees = 24 × 30 Step 3: Break it down for clarity. First, multiply 24 by 3: 24 × 3 = 72 Step 4: Since 30 = 3 × 10, we now multiply 72 by 10: 72 × 10 = 720 Step 5: Conclusion. The total number of apple trees is 720. Answer: 720

7. 1 × 50 = ? Answer: 50 Solution: 1 × 50 = 50.
8. The school is organizing a book fair and needs to set up tables. Each table can display 60 books. If there are 8 tables set up for the fair, how many books can be displayed in total? Answer: 480 Solution: Identify the number of books per table: 60 books Identify the number of tables: 8 tables Multiply the number of books per table by the number of tables: 60 × 8 Calculate 60 × 8 = 480 The total number of books that can be displayed is 480.
   Full step-by-step solution

   Step 1: Identify the number of books per table: 60 books Step 2: Identify the number of tables: 8 tables Step 3: Multiply the number of books per table by the number of tables: 60 × 8 Step 4: Calculate 60 × 8 = 480 Step 5: The total number of books that can be displayed is 480.

9. 0 × 70 = ? Answer: 0 Solution: Any number multiplied by 0 equals 0.