1. Splash Screen

2. Then/Now You have already found percents using the percent proportion. (Lesson 7–3) Compute mentally with percents. Estimate with percents.

3. Concept

4. Example 1 A Use a Fraction to Compute Mentally A. Find 50% of 46 mentally. Answer: 50% of 46 is 23. THINK:

5. Example 1 A Use a Fraction to Compute Mentally = 6

6. Example 1 CYP A A.41 B.164 C.16 D.40 A. Find 50% of 82 mentally.

7. Example 1 CYP A A.6 B.4 C.16 D.48 B. Find 25% of 24 mentally.

8. Example 2 Use Decimals to Compute Mentally A. Compute 10% of 54 mentally. Answer: 5.4 10% of 54 = 0.1 ● 54 or 5.4

9. Example 2B Use Decimals to Compute Mentally B. Compute 1% of 219 mentally. Answer: 2.19 1% of 219 = 0.01 ● 219 or 2.19

10. Example 2 Use Decimals to Compute Mentally C. Compute 20% of 50 mentally. Answer: 10 First, find 10% of 50 = 0.1 ● 50 or 5 Then, 20% is 2 ● 10%, so 20% of 50 = 2(10% of 50) = 2(5) = 10

11. Example 2 Use Decimals to Compute Mentally D. Compute 15% of 40 mentally. Answer: 6 First, find 10% of 40 = 0.1 ● 40 or 4 = 2 Think of 15% as 10% + 5% Finally add (10% of 40) + (5% of 40) = 4 + 2 = 6

12. Example 2A A.0.089 B.0.89 C.8.9 D.890 A. Find 10% of 89 mentally.

13. Example 2B A.0.0543 B.0.543 C.5.43 D.54.3 B. Find 1% of 543 mentally.

14. Example 2B A.56 B.8 C.24 D.16 C. Find 30% of 80 mentally.

15. Example 2B A.6 B.3 C.9 D.30 C. Find 15% of 60 mentally.

16. Example 3 Compute Mentally SHOPPING Garrett is shopping for a new video game. The original price of the game is $60.00. The game is 10% off. How much will Garrett save? Find 10% of $60. 10% of 60=0.10 ● 60Move the decimal point one place to the left. =6=6 Answer: Garrett will save $6.

17. Example 3 A.$4.20 B.$21.00 C.$42.00 D.$84.00 John has a coupon for a 10% discount. If he buys a television with a regular price of $420, how much will he save?

18. Example 4 A Estimate Percent of a Number A. Estimate 22% of 494. Answer: So, 22% of 494 is about 100.

19. Example 4 B Estimate Percent of a Number B. So,

20. Example 4 C Estimate Percent of a Number C. Estimate 49% of 61. Answer: So, 49% of 61 is about 30. 61 is about 60.

21. Example 4 D Estimate Percent of a Number D. Estimate 155% of 38. Answer: So, 155% of 38 is about 40 + 20 or 60. 155% is about 150%. 38 is about 40. 100% of 40 is 40. 50% of 40 is 20.

22. Example 4 CYP A A.100 B.152 C.160 D.80 A. Estimate 38% of 400.

23. Example 4 CYP B A.25 B.4.964 C.4 D.5 B. Estimate % of 2482.

24. Example 4 CYP C C. Which is the best estimate for 26% of 78? A.10 B.20 C.25 D.30

25. Example 4 CYP D A.135 B.46.5 C.49.29 D.180 D. Estimate 153% of 93.