1. Rounding
Decimals
So what’s
the point?
Get it?
PowerPoint

2. Rounding numbers
We round numbers to make them easier to use and understand while keeping them close to their actual value.

3. Here are some real-world examples where numbers are rounded:
Rounding numbers
Here are some real-world examples where numbers are rounded:
Sales tax – always rounded
to the nearest penny.
$ales Tax
Time/Distance/Amount – rounded for easier understanding.
Mental math – rounding numbers helps us do math in our heads.

4. Rounding
Whole Numbers
Review
Part 1:

5. Rounding Whole numbers
Let’s round some whole numbers!
Example 1:
Round the following number to the nearest hundred.
5,368
Step 1: Underline the hundred’s place.
Step 2: Look at the number to the right of
the underlined digit.

6. Rounding Whole numbers
5,368
Example 1 continued:
Round the following number to the nearest hundred.
= 5,400
Step 3: If the number on the right is 4 or less, leave the
underlined number alone, and turn all digits on
the right side of the underlined number into zeros. or
Step 3: If the number on the right is 5 or more, add one
to the underlined number, and then turn the rest
of the digits on the right into zeros.

7. Rounding Whole numbers
Example 2:
Round the following number to the nearest ten thousand.
683,261
= 68
0,000
Step 1: Underline the ten thousand’s place.
Step 2: Look at the number to the right of the 8.
Step 3: Leave 8 alone because 3 is “four or less.”
Step 4: All numbers to right of the underlined
number turn into zeros.

8. Rounding Whole numbers
Example 3:
Round the following number to the nearest ten.
496
= 50
Step 1: Underline.
Step 2: Look to the right of 9.
Step 3: Round the 9 up to 10 and carry the 1 over
to the 4, making it a 5.
Step 4: All numbers to right of the underlined
number turn to zero.
Let’s practice!

9. Rounding Whole number's Practice
Round the following numbers to the place indicated.
1) thousands; 14,023
3) millions; 63,502,019
5) hundred thousands; 181,215
7) tens; $641.43
2) tens; 21,485
4) hundreds; 757,839
6) ten thousands; 397,216
8) hundreds; 7,985
14,000
21,490
64,000,000
757,800
200,000
400,000
$640.00
8,000

10. Part 2:
Rounding Decimals

11. we still need to round decimals. Is there Sounds reasonably painless!
Rounding Decimals
I think
I get rounding, but
we still need to round decimals. Is there
any difference?
Sounds reasonably painless!
We follow the exact same steps, but at the end, instead of turning numbers into zeros, we just remove them!
Check this
out!

12. Rounding Decimals 1.252 = 1.25 2 Example 1: Step 1: Underline.
Round the following decimal to the nearest hundredth.
1.252
= 1.25 2
Step 1: Underline.
Step 2: Look to the right of 5.
Step 3: The 5 stays the same.
Step 4: Cut off all numbers to the right of the
underlined number.

13. Rounding Decimals 9.473 = 9.5 7 3 Example 2:
Round the following decimal to the nearest tenth.
9.473
= 9.5 7 3
Round the 4 to a 5, and remove all digits to the right of the underline number.

14. Rounding Decimals $3.985 = $3.99 Example 3: Round the 8 up to a 9.
Round the following money amount to the nearest penny.
$3.985
= $3.99
Round the 8 up to a 9.
Remove the 5.
Don’t forget the dollar sign!
Let’s practice!

15. Rounding Decimals’ Practice
Round the following decimals to each underlined place.
7. $7.4951
8. $862.99 9
0.62
1.732
3.8
9.87
1 or 1.0
$7.50
$860.00

16. Rounding Decimals’ Practice
Round the following numbers to the indicated place.
1) thousandths;
3) hundredths; 4.888
5) thousandths;
7) nearest penny; $55.386
2) tenths; 0.798
4) tenths;
6) hundredths; 4.996
8) nearest dime; $65.46
0.064
0.8
4.89
114.3
2.752
5 or 5.00
$55.39
$65.50