Finding a Percent of a Number

Two methods:

1.) Mental Math- (Only works for some percents)

2.) Multiplication method

Mental Math Finding Percents

50%Write 50% as a fraction in lowest terms.

Find 50% of 150. Find 50% of 240.

To find 50% divide by 2.Trick:

Mental Math Finding Percents

25%Write 25% as a fraction in lowest terms.

Find 25% of 32. Find 25% of 240.

To find 25% divide by 4.Trick:

Mental Math Finding Percents

20%Write 20% as a fraction in lowest terms.

Find 20% of 40. Find 20% of 350.

To find 20% divide by 5.Trick:

Mental Math Finding Percents

10%Write 10% as a fraction in lowest terms.

Find 10% of 50. Find 25% of 240.

To find 10% divide by 10.

Find 10% of 356.

Trick:

Mental Math Finding Percents

5%Write 5% as a fraction in lowest terms.

Find 5% of 80. Find 25% of 240.

To find 5% divide by 20.

Find 5% of 120.

Trick:

Mental Math Finding Percents

1%Write 1% as a fraction in lowest terms.

Find 1% of 70. Find 25% of 240.

To find 1% divide by 100.

Find 1% of 125.

Trick:

Mental Math Finding Percents

33 %Write 33.3% as a fraction in lowest terms.

Find of 51. Find 25% of 240.

To find 33.3% divide by 3.

Find of 126.

Trick:

Percent    Short cut

50%

25%

20%

10%

5%

1%

How could we find 15%?

Find 15% of 60. Find 15% of 42

How could we find 75%?

Find 75% of 400. Find 75% of 60

Hint- "of " means multiplication

Method two: Multiplying decimals

Convert the percent to a decimal and multiply

1.) Find 45% of 40 2.) Find 35% of 500

3.) What is 12% of 43? 4.) Find 80% of 35

Demonstrate Understanding: Find each percent, you may use either method.

1.) 20% of 95 2.) 52% of 96

3.) 15% of 82 4.) of 147

5.) 26% of 26 6.) 30% of 250

7.) There were 40 questions on the test, if Samantha got 80% correct, how many questions did she get right?