Multiply 4-Digit by 1-Digit

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Multiply 4-Digit by 1-Digit · Grade 4 · Worksheet 1

1. The school library is buying new books for the fourth grade classrooms. They need 24 books for each of the 15 classrooms. How many books does the library need to buy in total? Answer: 360 Solution: We need to find the total number of books for 15 classrooms, with each classroom getting 24 books. Write the multiplication.
   Full step-by-step solution

   Step 1: Understand the problem. We need to find the total number of books for 15 classrooms, with each classroom getting 24 books. Step 2: Write the multiplication. Total books = number of classrooms × books per classroom Total books = 15 × 24 Step 3: Break down the multiplication for easier calculation. We can split 24 into 20 + 4. So, 15 × 24 = 15 × (20 + 4) Step 4: Use the distributive property. First, multiply 15 × 20: 15 × 20 = 300 Step 5: Multiply 15 × 4: 15 × 4 = 60 Step 6: Add the two results. 300 + 60 = 360 Step 7: Conclusion. The library needs to buy 360 books in total.

2. A toy factory produces 1,245 toy cars each day. If the factory operates for 28 days in a month, how many toy cars does it produce in one month? Answer: 34860 Solution: The factory produces 1,245 toy cars each day and operates for 28 days.
   Full step-by-step solution

   Step 1: The factory produces 1,245 toy cars each day and operates for 28 days. Step 2: Multiply the daily production by the number of days: 1,245 × 28 Step 3: First, multiply 1,245 by 20: 1,245 × 20 = 24,900 Step 4: Then multiply 1,245 by 8: 1,245 × 8 = 9,960 Step 5: Add the two results together: 24,900 + 9,960 = 34,860 Step 6: The factory produces 34,860 toy cars in one month.

3. 1,245 × 38 = ? Answer: 47310 Solution: Multiply 1,245 by 30 1,245 × 30 = (1,245 × 3) × 10 = 3,735 × 10 = 37,350 Multiply 1,245 by 8 1,245 × 8 = 9,960 37,350 + 9,960 = 47,310 The answer is 47,310.
   Full step-by-step solution

   Step 1: Multiply 1,245 by 30 1,245 × 30 = (1,245 × 3) × 10 = 3,735 × 10 = 37,350 Step 2: Multiply 1,245 by 8 1,245 × 8 = 9,960 Step 3: Add the two results together 37,350 + 9,960 = 47,310 The answer is 47,310.

4. Liam is helping his school organize a book donation drive. Each classroom collected 125 books, and there are 24 classrooms participating. How many books were collected in total? Answer: 3000 Solution: Identify what you know: Each classroom collected 125 books, and there are 24 classrooms. To find the total number of books, multiply the number of books per classroom by the number of classrooms.
   Full step-by-step solution

   Step 1: Identify what you know: Each classroom collected 125 books, and there are 24 classrooms. Step 2: To find the total number of books, multiply the number of books per classroom by the number of classrooms. Step 3: Set up the multiplication: 125 × 24 Step 4: Break it down: First, multiply 125 by 20: 125 × 20 = 2500 Step 5: Then, multiply 125 by 4: 125 × 4 = 500 Step 6: Add the two results together: 2500 + 500 = 3000 Step 7: The total number of books collected is 3000.

5. A school is organizing a field trip and needs to pack lunches. Each student will receive a lunch box that contains 4 items. If there are 325 students going on the trip, how many total lunch items need to be packed? Answer: 1300 Solution: Each student gets 1 lunch box, and each lunch box contains 4 items. There are 325 students in total. Determine the total number of lunch items needed.
   Full step-by-step solution

   Step 1: Understand the problem. Each student gets 1 lunch box, and each lunch box contains 4 items. There are 325 students in total. Step 2: Determine the total number of lunch items needed. Since each student gets 4 items, the total number of items is: Total items = (Number of students) × (Number of items per student) Step 3: Substitute the numbers into the equation. Total items = 325 × 4 Step 4: Perform the multiplication. First, multiply 300 × 4 = 1200 Then, multiply 25 × 4 = 100 Add them: 1200 + 100 = 1300 Step 5: State the final answer. The school needs to pack 1300 lunch items in total.

6. 245 × 38 = ? Answer: 9310 Solution: Multiply 245 by 30: 245 × 30 = 7,350 Multiply 245 by 8: 245 × 8 = 1,960 Add the two results: 7,350 + 1,960 = 9,310 The answer is 9,310.
   Full step-by-step solution

   Step 1: Multiply 245 by 30: 245 × 30 = 7,350 Step 2: Multiply 245 by 8: 245 × 8 = 1,960 Step 3: Add the two results: 7,350 + 1,960 = 9,310 The answer is 9,310.

7. A rectangular swimming pool is drawn with a length of 25 meters and a width of 12 meters. A border of square tiles is placed around the entire edge of the pool, with each tile measuring 0.5 meters on each side. How many tiles are needed to create this border? Answer: 148 Solution: Perimeter = 2 × (length + width) = 2 × (25 + 12) = 2 × 37 = 74 meters Each tile measures 0.5 meters on each side Number of tiles = Perimeter ÷ Tile length = 74 ÷ 0.5 74 ÷ 0.5 = 74 ÷ (1/2) = 74 × 2 = 148 148 tiles × 0.5 meters each = 148 × 0.5 = 74 meters This matches the perimeter we calculated.
   Full step-by-step solution

   Step 1: Find the perimeter of the rectangular pool Perimeter = 2 × (length + width) = 2 × (25 + 12) = 2 × 37 = 74 meters Step 2: Determine how many tiles fit along the perimeter Each tile measures 0.5 meters on each side Number of tiles = Perimeter ÷ Tile length = 74 ÷ 0.5 Step 3: Calculate the division 74 ÷ 0.5 = 74 ÷ (1/2) = 74 × 2 = 148 Step 4: Verify the answer 148 tiles × 0.5 meters each = 148 × 0.5 = 74 meters This matches the perimeter we calculated. The answer is 148.