Math 7 - Percents Review

Find the NEW

100

Start at 10, increase by 20%

12

200

Start at 30, increase by 12%

33.6

300

Start at 300, decrease by 25%

225

400

Start at 5, decrease by 10%

4.5

500

A grocery store sold 128 water bottles yesterday. Today, they sold 50% more. How many water bottles did the grocery store sell today?

192

Find the ORIGINAL

100

A decrease of 25% left Ms. Gil with 213 pencils. How many did she start with?

300 pencils

200

Mya has 391 followers on Instagram. This is an increase of 15% from last month. How many followers did Mya have last month?

340

300

After a 25% discount, the price of a T-shirt was $12. What was the price before the discount?

$16

400

Compared to last year, the population of Boom Town has increased by 25%. The population is now 6,600. What was the population last year?

5,280 (people)

500

The water level in a reservoir is now 52 meters. If this was a 23% increase, what was the original depth?

43.33 ft

Find the % Change

100

Increase from 8 to 12, what is the percent change?

50% (increase)

200

Decrease from 20 to 10, what is the percent change?

50% (decrease)

300

Increase from 100 to 120, what is the percent change?

20% (increase)

400

1. Josh started a savings account with $1,800. After a year, his savings is at $1,944. What is the percent increase?

8%

500

The basketball team had $800 for their travel trip. After the trip, they have $163.24 left. What is the percent decrease?

80%

Write an equation

100

Write an equation:

The water level in a reservoir is now 52 meters. If this was a 23% increase, what was the initial depth?

52=1.23x

or

y=1.23x

200

Write an equation:

The snow is now 52 inches deep. If this was a 77% decrease, what was the initial depth?

52=0.23x

or

y=0.23x

300

What equation could you write to find a 10% increase of a number?

Either:

y=1.10x

"or"

"new"= 1.10 * "original"

400

Write an equation:

A movie theater decreased the size of its popcorn bags by 20%. If the old bags held 15 cups of popcorn, how much do the new bags hold?

"new"=1.20*15

or

y=1.20x

500

Write an equation:

After a 25% discount, the price of a T-shirt was $12. What was the price before the discount?

12=0.75x

or

y=0.75x

% Misc.

100

What are two strategies that we have used to solve percent problems?

tables, equations, double number lines and tape diagrams

200

How do you change from a percent to a decimal?

Divide the % by 100

300

How do you change from a decimal to percent?

Multiply the decimal by 100

400

Write 127% as a decimal.

1.27

500

Write 8% as a decimal.

0.08