1. Rounding Whole Numbers to the Nearest 10 and 100
Objective: I can round numbers to the nearest 10 and 100.

2. Review Order the following numbers from greatest to least.
_______________________
_______________________
Order the following numbers from least to greatest.
4, , , ,581 _______________________
9, , , ,972 _______________________

3. How do I round whole numbers using a number line?
First learn the number line song!
Rounding’s not that hard to do
Let me teach the rules to you
For the numbers 5 through 9
Round that number up the line
For the numbers 4 or less
Round that number down or yes!

4. How do I round whole numbers using a number line?
Step 1: First figure out what place value you are rounding to.
Example: Round 53 to the nearest 10.
Step 2: Since we are concerned with the 10s place, construct a number line with 50 as the lowest number, 55 as the middle number, and 60 as the highest number.
Example: 50 55 60

5. How do I round whole numbers using a number line?
Step 3: Now plot 53 on the number line.
Example:
Step 4: Analyze how close 53 is to 50 and to 60. Since 53 is closer to 50, 53 rounded to the nearest 10 is 50. 50 53 55 60 50 53 55 60

6. Let’s try to round! Let’s try to round 672…. What is the first step?
Figure out what place value we are rounding to!
Okay so, we need to round to the nearest 672 to the nearest 100… What is next?
Well, since we are concerned with the 100s place, we need to construct a number line with 600 as the lowest number, 650 as the middle number, and 700 as the highest number.
Move to see the answer.
Move to see the answer.
600
650
700

7. What’s next? Now that we have our number line… what’s next?
Put 672 on the number line!
Awesome! Now what?!
Check to see if 672 is closer to 600 or 700 for the final answer!
Move to see the answer.
600
650
672
700
Move to see the answer.
600
650
672
700

8. Guided Practice
DIRECTIONS: Using a number line, round the following numbers to the nearest 10 and 100.
244 rounded to the nearest 10 is ________.
251 rounded to the nearest 100 is __________.

9. Student Practice
DIRECTIONS: Using a number line, round the following numbers to the nearest 10 and 100.
Round 165 to the nearest 10.
Round 144 to the nearest 10.
Round 182 to the nearest 10.
Round 151 to the nearest 100.
Round 319 to the nearest 100.
6. Round 792 to the nearest 100.