1. 5-Minute Check
Round to the nearest whole number.
1.45
26.72
53.54
67.15
Round to the nearest tenth.
3.16
9.35
48.51
92.64

2. Estimate Decimal and Sum Differences
By Mr. Bales

3. Objective
By the end of the lesson, you will be able to use rounding to estimate sums and differences.
Standard 4NS2.1 – Students will be able to estimate and compute the sum or difference of whole numbers and positive decimals to two places.

4. Introduce
Let’s review the rounding rules. According to the song, what is the first thing that you do? Second? Last?
Look at the following dollar amounts and round to the nearest whole dollar:
$56.75
$32.42
$22.63
$18.35
Rounding decimals like these can be used to estimate sums and differences.

5. Teach Look at this decimal4.56
What place value do you look at when you round to the nearest whole number? What number is it in this decimal?
Is the digit in the hundredths place important when rounding to the nearest whole number? Why or why not?
How do you think rounding decimals can help you estimate sums and differences?

6. Get Ready to Learn
Soumya is going white water rafting with her family. During their first day, they will travel 6.5 miles before lunch and 8.75 miles after lunch. ABOUT how far will they travel on their first day?
Concept in Motion!!

7. Rounding Decimals 6.50 – 7 8.95 – 9 7 + 9 = 16 miles
To estimate the sums and differences of decimals, round each decimal to the nearest whole number. Then add or subtract.
6.50 – 7
8.95 – 9
7 + 9 = 16 miles

8. Let’s hear from Mr. Hardesty!! Game time!!

9. Bales Bucks!! Estimate. Round to the nearest whole number. 1.5 + 2.3
5.4 – 3.61
62.8 – 9.5
$ $3.25
46.37 – 7.3

10. Assignment
Page #’s
Get them all correct - No Math Homework (over the weekend)