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34 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Integers
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Whole numbers (-6, -2, 0, 1, 3, 7)
Not fractions Consecutive Integers - listed in order with none missing |
Ex. 148
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Digits
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0, 1, 2, 3, 4, 5, 6, 7, 8, 9
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Integers are composed of digits
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Absolute value
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Distance away from 0 (always a positive number).
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Ex. Absolute value for -3 is 3, for 2 is 2, etc.
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Order of Operations
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PEMDAS (Parentheses, Exponents, Multiplication --> Division, Addition --> Subtraction)
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Reducing Fractions
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Divide numerator and denominator by factors common to both
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Ex. 16/20 divided by 4 = 4/5
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Multiplying Fractions
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Multiply straight across; reduce fractions in multiplication across the multiplication sign
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4 10 1 2 2
-- X -- = -- X -- = -- 5 12 1 3 3 |
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Dividing Fractions
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Turn second fraction upside down before multiplying
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Fractions within Fractions
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Rewrite horizontally
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Adding/Subtracting Problems
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With a common denominator: add across numerators and keep denominator.
Without: find common denominator and go from there. |
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0.01 = 1/100 = 1%
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0.1 = 1/10 = 10%
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0.2 = 1/5 = 20%
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0.25 = 1/4 = 25%
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0.333 = 1/3 = 33 1/3%
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0.4 = 2/5 = 40%
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0.5 = 1/2 = 50%
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0.6 = 3/5 = 60%
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0.666 = 2/3 = 66 2/3%
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0.75 = 3/4 = 75%
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0.8 = 4/5 = 80%
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1.0 = 1/1 = 100%
2.0 = 2/1 = 200% |
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Decimal to %
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Move decimal point two places to the right
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Ex. .45 = 45%
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Percent Change
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Difference
-------------- X 100 Original |
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Associative Law
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When adding or multiplying a series of numbers you can regroup however you'd like
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(a+b)+(c+d) = a+(b+c+d)
(ab)(cd) = a(bcd) |
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Distributive Law
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A (B + C) = AB + AC
A (B - C) = AB - AC |
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Factoring and Unfactoring
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Rewriting xy+xz as x(y+z) = factoring
Rewriting x(y+z) as xy+xz = unfactoring |
If you can factor or unfactor on the GRE, do it
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Plugging in Numbers
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Try normal, easy numbers like 2, 5; 10 or 100 for percentages; 30 or 120 for minutes/seconds; and then try weird numbers like 0 or -1.
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Average Pie
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( Total ) ( )
(-----------) divide (---------) ( N | X) ( | ) X |
Ex. 63 15
----- ------ 7|9 3|5 |
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Bell Curve
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_____
/ | \ ___/ | \___ ---------------------- 2|14|34|34|14|2 % |
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Rate Pie
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( Distance/Amt)
( -------------------- ) (Time | Rate ) |
Ex.
150 -------- 3 | 50 |
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Ratios
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Treat as fractions:
Cross multiply, find common denominators, reduce, etc. |
Ratio Box:
x y total Ratio Multiply by Real |
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Probability
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p = # of poss. outcomes for condition
------------------------------ number of total possible outcomes |
Probability of a series of events: multiply probabilities of the individual events
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Factorials (!)
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That number times every positive whole number smaller than itself down to one
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Permutation
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Arrangement of things in a particular order
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How many slots you have, number of options for each slot, and multiply them.
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Combination
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Order is irrelevant
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How many slots you have, fill in the slots as you would a permutation, and then divide by the factorial of the number of slots.
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FOIL
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First, Outer, Inner, Last
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(x+4)(x+3)
x*x, x*3, 4*x, 4*3 |
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2 2
X - Y |
(x+y)(x-y)
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2 2
X - Y = (X+Y)(X-Y) |
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2
(X+Y) |
2 2
X + 2XY + Y |
2 2 2
(X+Y) = X + 2XY + Y |
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2
(X-Y) |
2 2
X - 2xy + Y |
2 2 2
(X-Y) = X - 2XY + Y |
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(+) (+) =
(-) (-) = (+) (-) = |
+
+ - |
(+) (+) = +
(-) (-) = + (+) (-) = - |
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even
NEGATIVE = |
Positive
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even
NEGATIVE = Positive |
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odd
NEGATIVE = |
Negative
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odd
NEGATIVE = negative |
