GRE Quantitative
Fraction > Decimal: 1/1000
0.001
Fraction > Decimal: 1/600
0.001666....
Fraction > Decimal: 1/100
0.01
1/40
0.025
Fraction > Decimal: 1/20
0.05
Fraction > Decimal: 1/10
0.1
Fraction > Decimal: 1/9
0.11111.....
Fraction > Decimal: 1/8
0.125
Fraction > Decimal: 1/6
0.16667
Fraction > Decimal: 1/5
0.2
Fraction > Decimal: 1/4
0.25
Fraction > Decimal: 3/8
0.375
Fraction > Decimal: 2/5
0.4
Fraction > Decimal: 1/2
0.5
Fraction > Decimal: 3/5
0.6
Fraction > Decimal: 5/8
0.625
Fraction > Decimal: 2/3
0.66667
Fraction > Decimal: 3/4
0.75
Fraction > Decimal: 7/9
0.7777....
Fraction > Decimal: 4/5
0.8
Fraction > Decimal: 5/6
0.83333.....
Fraction > Decimal: 7/8
0.875
Finding GCF
1. Factor both #'s 2. Find the highest power of 2 both #'s have in common. 3. Find highest power of 3 both have in common 4. Find highest power of 4 both have in common 5. Multiply the common factors (with their exponents) to get GFC.
Finding LCM
1. Find GCF. 2. Divide GCF from both numbers. 3. Multiply the GCF by both multiples found above. or... use [LCM= (P x Q)/GCF]
Equation for percent *increase*:
1. m = 1 + (p% as decimal) 2. m x initial price = new increased price
Equation for percent *decrease*:
1. m = 1- (p% as decimal) 2. m x initial price = new decreased price
First 15 perfect squares
1=1 2=4 3=9 4=16 5=25 6=36 7=49 8=64 9=81 11=121 12=144 13=169 14=196 15=225
Prime numbers less than 20:
2, 3, 5, 7, 11, 13, 17, 19
Prime numbers between 20 and 60:
23, 29, 31, 37, 41, 43, 47, 53, 59
Circumference of a circle
2πr
Pythagorean triples
3-4-5 5-12-13 7-24-25 8-15-17
Area of a circle formula
A=πr²
Divisiblity Rules for 2:
All even #'s are divisible by 2. Check to see if last digit is even.
Total Area of a Cylinder
Area = 2πrh + 2πr²
Add or subtract "likes", we get an _____ number.
EVEN
Multiplying even and odds: As long as there is at lease ONE even factor in a product, the product will be ____.
EVEN
Divisiblity Rules for 4:
If the last two digits (one's and ten's place) form a 2-digit # that is divisible by 4, then the entire # is divisible by 4.
Divisiblity Rules for 3:
If the sum of the digits is divisible by 3, then the number is divisible by 3. Ex: with 135; 1 + 3 + 5 = 9. Since 9 is divisible by 3, that means 135 is also divisible by 3.
Divisiblity Rules for 9:
If the sum of the digits is divisible by 9, then the number is divisible by 9. Ex: with 1296; 1 + 2 + 9 + 6 = 18. Since 18 is divisible by 9, that means 1296 Is also divisible my 9.
Lateral Area of a Cylinder
LA = 2πrh
If sequential percent changes.... find multiplier for each percent change, then _____ all multipliers.
Multiply
Divisibility Rules for 6:
Must be an even number and sum of digits is divisible by 3. Ex: with 1296; 1 + 2 + 9 + 6 = 18. Since 18 is an even # and divisible by 3, then 1296 must be divisible by 6.
Add or subtract "unlikes", we get an ____ number.
ODD
Divisiblity Rules for 5:
Only if last digit is 0 or 5, it is divisible by 5.
PROFIT equation
Profit = Revenue - Cost
Total surface area of rectangular prism
SA = 2hw + 2hd + 2wd
Total surface area of cube
SA = 6s^2
True or false.... NEVER double round. Ex of double rounding: 6.48 > 6.5 > 7
True. Instead... 6.48 > 6
Volume of a rectangular prism
V = L x W x D
Volume of a cube formula
V=s^3
Volume of a Cylinder Formula
V=πr²h
Equation for arc length
arc length/2πr = angle/360
Area of a sector
area of sector/πr^2 = angle/360 or area of sector = angle/360 x πr^2
Terms: "is" means ____ "of" means ____
is = equal of = multiply
Sign rules for division: Same sign =____ different sign = ____
same = positive different = negative
Sign rules for multiplication: Same sign = ____ Different sign = ____
same = positive different = negative