7th Grade Math Review

All about Circles

100

A circle has a radius of 8m. What is the diameter?

16m.

200

A Circle has a radius of 5ft. Find the area. Round to the hundredths place.

Remember: Pi x r²

78.5ft²

300

A Circle has a radius of 10ft. Find the area. Round to the hundredths place.

Remember: Pi x r²

314.1ft²

400

A Circle has a diameter of 8ft. Find the area. Round to the hundredths place.

Remember: Pi x r²

50.2ft²

500

A semicircle has a diameter of 10ft. Find the circumference.

Remember Circumference = 2 x Pi x r

31.4ft²

Vocabulary

100

1. Define area.

2. Explain how to get the area of a square/rectangle.

3. Explain how to get the area of a triangle.

1. Area is the inside space 

2. Square = L x W

3. Triangle = B x H divide by 2

200

What is the MOST accurate way to measure data? What is the second most accurate way?

Most accurate = Mean

Second most = Median

300

If a customer gives a 20% tip at a restaurant, what exactly does that mean? How do you calculate it.

It's 20% of the bill. Take the price and mutiply by 20% (0.2).

400

What is the constant of proportionality? What do you do with your x and your y values?

It's a comparison of y to x. Just divide y by x.

500

When you have an inequality like this:

-2x > 10

What happens when you are multiplying or dividing by a negative number?

When you multiply or divide by a negative for an inequality, the sign flips.

Laws of Exponents

100

3³

27

200

3³ x 3³

3⁶ 

OR 729.

300

5⁶ / 5²

^{Note: the / means divided by}

5⁴

^{OR 625.}

400

(2⁴ )⁴

2¹⁶

^{Power to a power = Multiply the exponents!}

500

(3³)² / 3²

3⁴

Equations and Inequalities

100

5x = 25

Solve for x.

x = 5

200

12x + 7 = 91

x = 7

300

1/2x - 5 = 3

Note: the 1/2 is a fraction.

x = 16

400

19x > 38

Solve for x. Your answer should NOT have an equal sign.

x > 2

500

-2x > -15

Solve for x.

x < 7.5

Don't forget to FLIP THE SIGN!

Proportional Relationships

100

5:12

10:24

Are these two ratios proportional?

Yes.  

5: 12 multiply both sides by 2 = 10:24

200

15:45

3:x

Solve for x.

x = 15.

15:45 divide both sides by 3.

3:15

300

A train travels 250 miles in 2 hours. What was it's speed in miles per hour.

125 mph.

Miles per hour = Miles divided by Hours

400

There are five pencils for every two students. How many pencils will there by for 12 students?

30 pencils.

2 x (6) = 12

5 x (6) = 30

500

A scale drawing of a boat has 1cm = 10 ft. The boat's actual size is 340 feet. How many centimeters is the drawing of the boat?

34cm.

1:10

x:340

Multiply both sides by 34.