1. Rounding Decimal Numbers
Sometimes close enough is good enough!

2. Molly has $16 in her pocket
She buys:
3 $1.89 each
3 $2.19 each
3 Large French $ $1.79 each
Does she have enough money?

3. About how much will it cost to fill up?
Gas costs $1.79 per gallon
I’m running on empty and I have a 20 gallon tank on my truck……
About how much will it cost to fill up?

4. You have one hour to take a 50 question test.
About how much time can you spend on each question?
Close enough is good enough!

5. The rounding poem Find your number Look right next door
4 or less, just ignore
5 or more add one more!

6. Rounding Whole Numbers
Round 474 to the closest hundred.
474
Find your number
Look right next door
Four or less, just ignore
Five or more, add one more

7. 474 Rounded to the hundreds becomes 500
Round 474 to the closest 10’s
474
Just ignore - 470

8. Try These
4,215
394 27
127,591
638

9. What about decimal numbers
The same rules (and poem) apply!
Round to the closest hundredths
4.167
Find your number
Look right next door
4.17

10. Remember
If you are asked to round to the nearest tenth…….your answer stops at the tenth place!
Example: Round to the closest tenth would be 42.7

11. Special Case! Rounding a 9
Round to the closes hundredths
Since there is a “9” in the hundredths place consider the tenth and hundredths together – 19 – do you leave it at 19 or move it to 20?

12. Round 4.95 to the closest tenth
Since there is a “9” in the tenth spot consider the ones and tenths together…… should you leave it at 49 or move it to 50?
4.95 rounded to the nearest tenth is 5.0

13. Try these 4.56 4.6 5.32 5.3 0.98 1.0 Round to hundredths
Round to tenths:
4.56
4.6
18.784
18.78
5.32
5.3
9.46
9.456
10.00
0.98
1.0
9.997

14. Homework
Page 600
Lesson 3-3 at the top of the page
1-20