Round Multi-Digit

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Answer Key & Explanations

Round Multi-Digit · Grade 4 · Worksheet 2

1. The school library is collecting books for a reading drive. On Monday, they collected 347 books. On Tuesday, they collected 482 books. On Wednesday, they collected 219 books. To the nearest hundred, how many books did the library collect in total over these three days? Answer: 1000 Solution: Monday: 347 Tuesday: 482 Wednesday: 219 347 + 482 = 829 829 + 219 = 1048 So the total number of books collected is 1048. To round 1048 to the nearest hundred, look at the tens digit.
   Full step-by-step solution

   Let's go step by step. **Step 1: Add the books collected each day** Monday: 347 Tuesday: 482 Wednesday: 219 First, add Monday and Tuesday: 347 + 482 = 829 Now add Wednesday's books: 829 + 219 = 1048 So the total number of books collected is 1048. **Step 2: Round to the nearest hundred** To round 1048 to the nearest hundred, look at the tens digit. The tens digit is 4 (in 1048, the number is 1048 → tens digit is 4). If the tens digit is less than 5, we round down; if 5 or more, we round up. Here, tens digit is 4, so we round down. 1048 rounded to the nearest hundred is 1000. **Step 3: Conclusion** The library collected about 1000 books to the nearest hundred. **Final answer:** 1000

2. Matiu is looking at a map of New Zealand on a grid where each square unit represents 1 kilometer. The map shows a rectangular lake. The length of the lake measures 2,845 units and the width measures 1,236 units. To help estimate the area for a school project, Matiu needs to round both dimensions to the nearest hundred. What is the length rounded to the nearest hundred, and what is the width rounded to the nearest hundred? Write your answer as 'length, width' (for example, '2800, 1200'). Answer: 2800, 1200 Solution: Round the length 2,845 to the nearest hundred. The hundreds digit is 8 (in the 800s place). The tens digit is 4.
   Full step-by-step solution

   Step 1: Round the length 2,845 to the nearest hundred. The hundreds digit is 8 (in the 800s place). The tens digit is 4. Since 4 is less than 5, we do not round up. So 2,845 rounds down to 2,800. Step 2: Round the width 1,236 to the nearest hundred. The hundreds digit is 2 (in the 200s place). The tens digit is 3. Since 3 is less than 5, we do not round up. So 1,236 rounds down to 1,200. Step 3: Write the answer as 'length, width'. The answer is 2800, 1200.

3. Round 6,829 to the nearest hundred. Answer: 6,800 Solution: Identify the hundreds place in 6,829. The hundreds digit is 8. Look at the digit to the right (tens place), which is 2.
   Full step-by-step solution

   Step 1: Identify the hundreds place in 6,829. The hundreds digit is 8. Step 2: Look at the digit to the right (tens place), which is 2. Step 3: Since 2 is less than 5, we round down. Step 4: Keep the hundreds digit (8) the same, and change all digits to the right to zeros. Step 5: 6,829 rounded to the nearest hundred is 6,800.

4. Emma is looking at a large number line drawn on the classroom floor. The number line starts at 4,500 and ends at 5,500. The tick marks show every hundred. She places a beanbag on the number 4,835. To the nearest hundred, what number is the beanbag closest to? Answer: 4,800 Solution: Identify the two hundreds that surround 4,835. The hundred below is 4,800 and the hundred above is 4,900. Look at the tens digit of 4,835.
   Full step-by-step solution

   Step 1: Identify the two hundreds that surround 4,835. The hundred below is 4,800 and the hundred above is 4,900. Step 2: Look at the tens digit of 4,835. The tens digit is 3 (since 4,835 = 4,800 + 35). Step 3: When rounding to the nearest hundred, if the tens digit is 0, 1, 2, 3, or 4, we round down to the lower hundred. If it is 5, 6, 7, 8, or 9, we round up. Step 4: Since the tens digit is 3, we round down. Step 5: 4,835 rounded to the nearest hundred is 4,800. The answer is 4,800.

5. Round 3,478 to the nearest hundred. Answer: 3,500 Solution: 1. Identify the hundreds place: In the number 3,478, the hundreds place is the 4. So we are looking at 3,478.
   Full step-by-step solution

   Step-by-step solution: 1. Identify the hundreds place: In the number 3,478, the hundreds place is the 4. So we are looking at 3,478. 2. Look at the digit immediately to the right of the hundreds place (the tens place): The tens digit is 7. 3. Apply the rounding rule: If the tens digit is 5 or greater (5, 6, 7, 8, or 9), we round the hundreds place up by 1. If the tens digit is 4 or less (0, 1, 2, 3, 4), we keep the hundreds place the same. Here, the tens digit is 7, which is 5 or greater, so we round up. 4. Round up the hundreds place: The hundreds digit is 4. Rounding up means 4 becomes 5. All digits to the right of the hundreds place become zeros. 5. Write the rounded number: The thousands digit (3) stays the same. The hundreds digit becomes 5. The tens and units digits become 0. So we get 3,500. Final answer: 3,500

6. A rectangular garden is drawn on a grid where each square unit represents 1 square meter. The garden spans 12 units in length and 8 units in width. What is the area of the garden in square meters? Answer: 96 Solution: We have a rectangular garden drawn on a grid. Each square unit on the grid represents 1 square meter in real life. The length is 12 units, and the width is 8 units.
   Full step-by-step solution

   Step 1: Understand the problem. We have a rectangular garden drawn on a grid. Each square unit on the grid represents 1 square meter in real life. The length is 12 units, and the width is 8 units. Step 2: Recall the formula for the area of a rectangle. The area of a rectangle is given by: Area = length × width Step 3: Substitute the given values into the formula. Length = 12 units Width = 8 units Area = 12 × 8 Step 4: Perform the multiplication. 12 × 8 = 96 Step 5: Interpret the result. Since each grid square unit is 1 square meter, the area of the garden is 96 square meters. Final Answer: 96

7. Round 47,382 to the nearest thousand. Answer: 47,000 Solution: Identify the thousands place in 47,382. The thousands digit is 7, so the number is between 47,000 and 48,000. Look at the digit immediately to the right (hundreds place), which is 3.
   Full step-by-step solution

   Step 1: Identify the thousands place in 47,382. The thousands digit is 7, so the number is between 47,000 and 48,000. Step 2: Look at the digit immediately to the right (hundreds place), which is 3. Step 3: Since 3 is less than 5, we round down. Step 4: Keep the thousands digit (7) the same, and change all digits to the right (hundreds, tens, ones) to zeros. Step 5: 47,382 rounded to the nearest thousand is 47,000. The answer is 47,000.

8. Sophia is helping her town plan a new walking trail. The total length of the trail they have designed so far is 12,847 feet. The town council wants to report the approximate length to the nearest thousand feet for a funding application. What number should Sophia report? Answer: 13,000 Solution: Identify the number we are rounding: 12,847 The thousands digit is 2 (12,847). We are rounding to the nearest thousand, so we look at the hundreds digit, which is 8.
   Full step-by-step solution

   Step 1: Identify the number we are rounding: 12,847 Step 2: The thousands digit is 2 (12,847). We are rounding to the nearest thousand, so we look at the hundreds digit, which is 8. Step 3: Since the hundreds digit is 8, which is 5 or greater, we round up. Step 4: Rounding up means we increase the thousands digit by 1 (from 2 to 3) and change all digits to the right to zero. Step 5: 12,847 rounded to the nearest thousand is 13,000. The answer is 13,000.