8th Grade Math Review

Circle Basics

100

Definition of a radius.

A segment that has one endpoint at the center of a circle and the other endpoint on the circle. 

The length of the radius is 1/2 the length of the diameter.

200

The definition of diameter.

A chord that passes through the center of the circle from edge to edge.

The length of the diameter is twice the length of the radius.

300

The formula for the area of a circle.

πr²

note: π=pi

400

The formula for the circumference of a circle.

πd

note: π=pi

500

2πr is the formula for _______.

note: π=pi

Circumference

Proportions

100

Solve. 2/9 = 10/a

45

200

A ________________ is an equation stating that two ratios are equal.

Proportion

300

Using cross products, decide if these ratios form a proportion. YOU MUST SHOW YOUR WORK TO RECEIVE POINTS. 10/18; 15/27

Yes, they are proportional. 270=270

400

In the National Hockey League, the ratio of goalies to total players on a team is about 2 to 30. There are about 900 total players. How many goalies are in the league?

60

500

Which two numbers are NOT possible solutions for "x" and "y" in x/y = 3/8 A. 9,24 B. 6,16 C. 1.5, 6 D. 15,40

C. 1.5, 6

Hodge Podge

100

Solve. 5(8+n) = 300

52

200

Solve. 4 x l-5l

Note: x means times. It is not being used as a variable.

20

300

Simplify. 20 days to 480 hours

1 day to 24 hours

400

Simplify. 40cm : 2m

.2cm to 1cm

500

Evaluate. n+ (13 - n) /5 for n=8

9

Integers

100

3-26=

-23

200

-5 + 18 =

13

300

35/(-7)

-5

400

-54/ (-9)

6

500

37-(-9)

46

Linear Equations

100

Name the slope and y-intercept for y = 1/2x + 27

slope = 1/2, y-intercept = 27

200

Put in slope intercept form: 5/6x + y = 32

y = -5/6x + 32

300

What is the y-intercept for y= 1/2x + 4

4

400

Which could be the slope of a line going UPWARD from left to right? a) -1 b) 3/5 c) -6/2 d) -1/4

b) 3/5

500

Which ordered pair is a solution to BOTH? y = 2x - 2 and y = -x +4 a. (0,2) b. (2,2) c. (1,3) d. (2,3)

b. (2,2)