Multiply by 10s

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Multiply by 10s · Grade 3 · Worksheet 2

1. The school library is organizing books on new shelves. Each shelf can hold 40 books. If there are 8 shelves, how many books can the library display in total? Answer: 320 Solution: Each shelf holds 40 books There are 8 shelves Multiply the number of books per shelf by the number of shelves: 40 × 8 Calculate 40 × 8 = 320 The library can display 320 books in total.
   Full step-by-step solution

   Step 1: Each shelf holds 40 books Step 2: There are 8 shelves Step 3: Multiply the number of books per shelf by the number of shelves: 40 × 8 Step 4: Calculate 40 × 8 = 320 Step 5: The library can display 320 books in total.

2. A school is organizing a field trip and needs to pack lunches. Each student will get a lunch bag containing 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 the total number of cookies.
   Full step-by-step solution

   Let's go step-by-step. Step 1: Understand the problem. Each student gets 4 cookies. There are 60 students. We need the total number of cookies. Step 2: Think about the operation. If 1 student gets 4 cookies, then for 60 students, we multiply the number of students by the number of cookies per student. Step 3: Write the multiplication. Total cookies = 60 × 4 Step 4: Calculate. 60 × 4 = 240 Step 5: Interpret the result. The school needs to pack 240 cookies in total for all the students. Final answer: 240

3. 1 × 30 = ? Answer: 30 Solution: 1 × 30 = 30.
4. 0 × 30 = ? Answer: 0 Solution: Any number multiplied by 0 equals 0.
5. A toy factory produces 40 toy cars every hour. If the factory operates for 8 hours each day, how many toy cars does it produce in one day? Answer: 320 Solution: The factory produces 40 toy cars each hour. The factory operates for 8 hours each day. To find the total number of toy cars produced, multiply the number of cars per hour by the number of hours: 40 × 8.
   Full step-by-step solution

   Step 1: The factory produces 40 toy cars each hour. Step 2: The factory operates for 8 hours each day. Step 3: To find the total number of toy cars produced, multiply the number of cars per hour by the number of hours: 40 × 8. Step 4: Calculate 40 × 8 = 320. The factory produces 320 toy cars in one day.

6. 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 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 needed. 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 multiplication. 60 × 4 = 240 Step 5: State the final answer. The school needs to pack 240 cookies in total.

7. A community garden has 60 rows of tomato plants. Each row contains 30 tomato plants. How many tomato plants are there in total in the garden? Answer: 1800 Solution: Identify the number of rows: 60 rows Identify the number of plants in each row: 30 plants Multiply the number of rows by the number of plants in each row: 60 × 30 Calculate 60 × 30 = 1800 The total number of tomato plants is 1800.
   Full step-by-step solution

   Step 1: Identify the number of rows: 60 rows Step 2: Identify the number of plants in each row: 30 plants Step 3: Multiply the number of rows by the number of plants in each row: 60 × 30 Step 4: Calculate 60 × 30 = 1800 Step 5: The total number of tomato plants is 1800.

8. A school is organizing a field trip and needs to pack lunches. Each student gets a lunch box that contains 4 cookies. If there are 30 students going on the trip, how many cookies are needed in total? Answer: 120 Solution: Each student gets 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 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 expression. Number of cookies = number of students × cookies per student Number of cookies = 30 × 4 Step 4: Perform the multiplication. 30 × 4 = 120 Step 5: State the final answer. The school needs 120 cookies in total.

9. A factory produces 80 toy cars in one hour. If the factory operates for 30 hours, how many toy cars does it produce in total? Answer: 2400 Solution: The factory produces 80 toy cars in one hour. It operates for 30 hours. We need to find the total number of toy cars produced.
   Full step-by-step solution

   Step 1: Understand the problem. The factory produces 80 toy cars in one hour. It operates for 30 hours. We need to find the total number of toy cars produced. Step 2: Identify the operation needed. Since each hour produces the same number of toy cars, we multiply the number of cars per hour by the number of hours. Step 3: Write the multiplication. Cars per hour = 80 Hours = 30 Total cars = 80 × 30 Step 4: Perform the multiplication. First, multiply 80 by 3: 80 × 3 = 240 Step 5: Adjust for the full 30 hours. Since 30 = 3 × 10, we can also think of it as: 80 × 30 = 80 × 3 × 10 We already have 80 × 3 = 240, so now multiply by 10: 240 × 10 = 2400 Step 6: State the final answer. The factory produces 2400 toy cars in total.