Math

Question 1

degrees in a triangle (if you add all three angles)

Answer 1

180

Question 2

How to recognize a multiple of 3

Answer 2

Sum of all the digits is a multiple of 3

Question 3

How to recognize a multiple of 4

Answer 3

Last 2 digits are a multiple of 4

Question 4

How to recognize a multiple of 9

Answer 4

Sum of all the digits is a multiple of 9

Question 5

Mean, Median, Mode

Answer 5

Mean = average
Median = middle number
Mode = most common number

Question 6

Trick for finding mean of consecutive numbers

Answer 6

Find mean (or average) of the lowest and highest numbers

Question 7

Trick for finding sum of consecutive numbers

Answer 7

Remember that the average is the sum divided by number of terms (so sum is average times number of terms)

Use average of lowest and highest numbers to find average of the whole set

Number of terms is (high-low+1)

Question 8

Factor this into 2 binomials:
a(squared) + 2ab + b(squared)

Answer 8

(a + b) (squared)

Question 9

Factor this into 2 binomials:
a(squared) - 2ab + b(squared)

Answer 9

(a - b) (squared)

Question 10

Factor this into 2 binomials:
a(squared) - b(squared)

Answer 10

(a - b) (a + b)

Question 11

How many degrees along a straight line (if you add up all the angles)?

Answer 11

180

Question 12

Area of a triangle

Answer 12

1/2 (base) (height)

Question 13

Isosceles triangle

Answer 13

2 sides are the same (which means that 2 angles are also the same)

Question 14

Equilateral triangle

Answer 14

All 3 sides are the same, and each angle is 60 degrees

Question 15

Similar triangles

Answer 15

In 2 “similar triangles”, their angles are identical and the sides are proportional

(Ex: If you double one side to produce the 2nd triangle, you’ll double each of the other sides too)

Question 16

Pythagorean theorem (for right triangles)

Answer 16

a(squared) + b(squared) = c(squared)

Question 17

Special right triangles:
Sides 3:4:__
or
Sides 5:12:__

Answer 17

Sides 3:4:5
or
Sides 5:12:13

Question 18

Special right triangles: Trick for finding sides of a triangle with angles 30:60:90 degrees

Answer 18

If short leg is x…
Long leg is x(square root of 3)
Hypotenuse is 2x

Question 19

Special right triangles: Trick for finding sides of a triangle with angles 45:45:90 degrees

Answer 19

If each leg is x…
Hypotenuse is x(square root of 2)

Question 20

Area of a parallelogram

Answer 20

Area = (base) (height)

Question 21

Area of a trapezoid

Answer 21

Area = (average of parallel sides) (height)

Question 22

Circumference of a circle

Answer 22

2(pi)(r)

Question 23

Area of a circle

Answer 23

(pi)(r squared)

Question 24

Slope of a line

Answer 24

Rise / Run

Question 25

Simple interest formula

Answer 25

Interest = Principle(r)(t)

Question 26

Compound interest formula

Answer 26

Final balance = (Principle) x (1 + interest rate/c) (exponent t times c) (c is number of times the interest is compounded annually)

Question 27

Combined work formula (ex: If I work at this speed and you work at this speed, how long does it take with both of us working on it?)

Answer 27

(1/my time) + (1/your time) = (1/our time)

Question 28

Overlapping data sets (Ex: __ students studying spanish, __ studying french, __ studying neither; how many studying both?)

Answer 28

Group 1 + Group 2 + neither - both = Total

Question 29

4!

Answer 29

4 x 3 x 2 x 1

Question 30

0!

Answer 30

1

Question 31

Permutation vs. Combination

Answer 31

Order matters in a permutation; use logic to multiply out the number of possible outcomes (Ex: how many possibilities of runners coming in first, second, and third in a race) A combination is just pulling a subgroup from a larger group, and order doesn't matter; use the combination formula (Ex: how many possible groups of 3 staff members to be on a committee)

Question 32

Combination formula

Answer 32

C = n! / (k! (n-k)!) N is number in the larger group K is number you're choosing

Question 33

Standard deviation

Answer 33

Measure of how much the numbers in a set deviate from the mean

Question 34

0 raised to an exponent

Answer 34

0

Question 35

x raised to the exponent 1/2

Answer 35

square root of x

Question 36

Side lengths of a 30-60-90 triangle

Answer 36

x, x times square root of 3, 2x

Question 37

Side lengths of a 45-45-90 triangle

Answer 37

x, x, x times square root of 2

Question 38

Sum of angles in a polygon

Answer 38

(n-2)(180) n is number of sides

Question 39

Sum of angles in a triangle

Answer 39

180

Question 40

Congruent vs similar shapes

Answer 40

Congruent shapes have the same side lengths and angles (they can be mapped onto each other with just rotating, reflection, and/or translation) Similar shapes have the same angles but can be different sizes (dilation is also allowed when trying to map them onto each other)

Question 41

Area of a parallelogram

Answer 41

A = base (height)

Question 42

Area of a trapezoid

Answer 42

A = (average length of the two parallel lines) (height)

Question 43

Value of pi

Answer 43

About 3.14 (or to get closer, can use fraction 22/7)

Question 44

Volume of a cylindar

Answer 44

V = pi (r squared) (height)