📚 Topic Summary
Rounding helps us simplify numbers to make them easier to work with. When rounding a 3-digit number to the nearest ten, we look at the ones digit. If the ones digit is 0, 1, 2, 3, or 4, we round down, keeping the tens digit the same and changing the ones digit to 0. If the ones digit is 5, 6, 7, 8, or 9, we round up, increasing the tens digit by 1 (and possibly the hundreds digit too, if the tens digit is 9) and changing the ones digit to 0.
For example, to round 342 to the nearest ten, we look at the ones digit, which is 2. Since 2 is less than 5, we round down to 340. To round 348 to the nearest ten, we look at the ones digit, which is 8. Since 8 is greater than or equal to 5, we round up to 350.
🔤 Part A: Vocabulary
Match the terms with their definitions:
| Term |
Definition |
| 1. Rounding |
A. The digit in the rightmost place |
| 2. Nearest Ten |
B. Simplifying a number to a nearby value |
| 3. Ones Digit |
C. The tens place value you want to round to |
| 4. Round Up |
D. To increase the tens digit when rounding |
| 5. Round Down |
E. To keep the tens digit the same when rounding |
✍️ Part B: Fill in the Blanks
When rounding to the nearest ten, look at the ______ digit. If that digit is 5 or more, we ______ up. If that digit is less than 5, we ______ down. Rounding makes numbers easier to ______. When rounding 234 to the nearest ten, we get ______.
🤔 Part C: Critical Thinking
Explain a real-life situation where rounding to the nearest ten might be helpful. Give a specific example.