math formula Flashcards
length of a diagonal inside a 3d figure
L2 x W2 x H2 = D2
add fractions
need same denominator
multiplying fractions
reduce first, multiply across
dividing fractions
find reciprocal of 2nd fraction, then multiply
comparing fractions
use bowtie method
convert mixed number to a fraction
multiply whole number by denominator then add to the numerator= new numerator over same denominator
percent increase
(difference over original) x100
Exponent rule acronym
MADSPM
Multiplying exponents
add them
Dividing exponents
Subtract them
Exponents with a power
multiply them
Negative exponents
put a 1 over the whole number, its then positive
When can square roots be added/subtracted
when the number inside the square is the same
When can square roots be multiplied
anytime
when can square roots be divided
anytime, sqrt(a/b) = sqrt(a) / sqrt(b)
Simplifying square roots
find ways to factor where one of the #’s is a perfect square, sqrt(20)= sqrt(4x5)= 2sqrt(5)
Prime numbers
(((not 0 and 1))))
2,3,5,7,11,13,17
Integers
all numbers -1,0,1 (cannot be fractions)
when can x2 (x squared) be positive
when x is positive OR negative
AVG pie
/ total/ # x avg
Rate pie
/Distance or amount/
time x rate
What do you need to solve a standard deviation problem
the mean
what do you need to find for ratio problems
the total
std deviation bell curve %’s
34%, 14%, 2%
