All About Percents! What is a percent?

A percent is a ratio in which the first term is compared to 100. The percent is the number of hundredths that represents the part to the whole.

How are fractions, decimals, and percents related to each other?

Fractions, decimals, and percents are related because they are three ways to show portions of a whole.

How do you change between fractions, decimals, and

percents?

How do you change between fractions, decimals, and

percents?

How do you change between fractions, decimals, and

percents?

Think: 525 thousandths is the same as 52.5 hundredths!

Easy percents to find!

Talk About ItHow can you write 4:5 as a percent?

Step 1: I know a percent is a ratio where the second term is always 100, so what is the relationship between 5 and 100?

Step 2: Well, 5 goes into 100 twenty times, and what I do to the second term, I have to do to the first term.

Step 3: So, I have to multiply 4 x 20 and that equals 80. Therefore, an equal ratio to 4:5 with the second term being 100 would be 80:100.

Step 4: And I know 80 out of 100 is 80%!

4:5 = 80:100 = 80%

How can you use fractions tomentally find a percent of a number?

You can use the fraction equivalents to find a percent of awhole number mentally, especially when the denominatoreasily divides into the whole number.

Finding a Percentof a Number

Sometimes, you need to find a number when a percent of it is

known.

Sales Tax and Discount• How do you find the sale price of an

item?

When stores have sales, prices of items are lowered. The discount is the amount to be taken off the original price. The discount can be given as a percent.

Ways to find a discount!

Find the Discount!

Original price $49.50Sale price: _________________

Find the Discount!

Original price $17.50Sale price: _________________

Find the Discount!

Chelsea Dark Vintage Skinny Jean

Original price $49.50Sale price: _________________

How do you calculate sales tax?A part of the receipt from Joyce’s purchase is shown at the right. If the sales tax is 6% of the subtotal, what was her total bill?

Find the TIP!Let’s say you received great service and you

want to give a 20% tip to your server.

How do you find 20% of $44.08??

How much money do you need in all?

Tides Restaurant

Find the TIP!Let’s say you received great service and you

want to give a 20% tip to your server.

How do you find 20% of $109.52??

How much money do you need in all?

Percent of Increase and Decrease

How can you use percents

to show change?Prices at a local electronics shop have changed over the

last decade. By what percent did the prices increase or decrease?

Percent of Increase and Decrease