Understanding Percents

Understanding Percents

Math Lesson 11-1

What is a percent?

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

Seven out of ten people prefer Crest toothpaste.

What PERECENTAGE of people prefer Crest toothpaste?

Use a grid to model percent!

 $\frac{7}{10}=\frac{70}{100}=70\%$  

Or use a proportion to find the percent!

We use x/100 as our second ratio because a percent is a part of 100.

We will be going through this method more tomorrow!

Question Time!

Multiple Choice

What symbol do we use to show percentage?

• @

• $

• %

• &

Multiple Choice

Percent is always referring to an amount out of _____.

• 1

• 10

• 100

• 1,000

Multiple Choice

What percentage is equal to half, 1/2, 0.5?

• 1%

• 12%

• 25%

• 50%

Multiple Choice

What percentage is equal to one whole?

• 1%

• 50%

• 99%

• 100%

What percentage of the grid is shaded pink?

Hint: this grid has 100 total squares!

Multiple Choice

What percentage of the grid is shaded pink?

• 6%

• 40%

• 50%

• 60%

What percentage of the grid is shaded green?

Multiple Choice

What percentage of the grid is shaded green?

• 10%

• 12%

• 14%

• 16%

What percentage of the grid is shaded purple?

Multiple Choice

What percentage of the grid is shaded purple?

• 38%

• 40%

• 42%

• 44%

Let's step it up!

Now determine the percentage using visuals that are not made up of 100 pieces - meaning you may need to do some converting!

What percentage of the stars are shaded red?

Hint: we see 10 stars shown, but percent refers to 100!

Multiple Choice

What percentage of stars are shaded red?

• 8%

• 18%

• 80%

• 88%

What percentage of stars are shaded yellow?

Hint: our total is out of 5 in the example, but percent is out of 100.

Multiple Choice

What percentage of the stars are shaded yellow?

• 10%

• 20%

• 50%

• 100%

What percentage of the number line is shaded black?

Hint: The number line is out of 10, percent is out of 100.

Multiple Choice

What percentage of the number line is shaded black?

• 9%

• 90%

• 99%

• 100%

All done!

Tell me how you're feeling about percents on the next slides...

Poll

How do you feel about determining percents when given a visual (picture)?

• GREAT

• OKAY

• NOT GREAT

Poll

Would you like to be in a small group for today to work on percents using visuals?

• YES

• NO