Obj. #1: Compute mentally with percents

Example 1 Find Percent of a Number Mentally

Obj. #2: Estimate with percents

Example 2 Estimate Percents

Example 3 Use Estimation to Solve a Problem

Practice and apply

Obj. #1: Compute mentally with percents

13-25 odd (alt. 13, 17, 21, 25)

Obj. #2: Estimate with percents

27-35 odd, 39 (alt. 27, 31, 35)

Maintaining Your Skills

47-60

Find 50% of 46 mentally.

Think: .

Think: of 46 is 23.

Answer: 50% of 46 is 23.

Obj. #1: Compute mentally with percents

Think: of 88 is 22.

Think: .

Find 25% of 88 mentally.

Answer: 25% of 88 is 22.

Obj. #1: Compute mentally with percents

Think: .

Find 70% of 110 mentally.

Answer: 70% of 110 is 77.

Think: of 110 is 11.

So, of 110 is 77.

Obj. #1: Compute mentally with percents

Obj. #1: Compute mentally with percents

Find the percent of each number mentally.

a. 50% of 82

b. 25% of 36

c. 80% of 60

Answer: 41

Answer: 9

Answer: 48

Obj. #1: Compute mentally with percents

Estimate 22% of 494.

22% is about 20% or .

494 is about 500.

of 500 is 100.

Answer: 22% of 494 is about 100.

Obj. #2: Estimate with percents

Estimate 63% of 788.

63% is about 60% or .

788 is about 800.

of 800 is 480.

Answer: 63% of 788 is about 480.

Obj. #2: Estimate with percents

1% of 1200 is 12.

Estimate of 1219.

1219 is almost 1200.

of 1219 is about or 3.Answer:

Obj. #2: Estimate with percents

Estimate 155% of 38.

155% means about 150 for every 100 or about 15 for every 10.

38 has about 4 tens.

Answer: 155% of 38 is about 60.

Obj. #2: Estimate with percents

Money A restaurant bill totals $21.35. You want to leave a 15% tip. What is a reasonable amount for the tip?

$21.35 is about $21.

So, 15% is about or $3.15.

Answer: A reasonable amount for the tip would be $3.

10% of $21 is $2.10. Move the decimal point1 place to the left.

5% of $21 is $1.05. 5% is one half of 10%.

Obj. #2: Estimate with percents

Obj. #2: Estimate with percents

a. Estimate 38% of 400.

b. Estimate 72% of 318.

c. Estimate of 2482.

d. Estimate 183% of 93.

Answer: 160

Answer: 210

Answer: 5

Answer: 162

Obj. #2: Estimate with percents

Money A restaurant bill totals $59.05. You want to leave a 15% tip. What is a reasonable amount for the tip?

Answer: A reasonable amount for the tip would be $9.

Obj. #2: Estimate with percents