Decimals, Fractions, and Percents Flashcards
Gross profit
Revenues minus expenses, or selling price minus cost
principal (loan or investment)
The original loan or investment amount
Simple annual interest
(principal) × (interest Rate) × (time)
Compound interest
based on the principal plus any interest already earned
Compound interest over n periods
(principal) × (1 + interest per period)^n − principal
Trick for solving word problems with percents and fractions
Organize information in a table
Equivalent Fraction
Same Number
Reducing to lowest terms
Divide each fraction’s numerator and denominator by the greatest common divisor
Greatest Common Divisor
Largest factor common to that numerator and that denominator
reciprocal of fraction
n / d is d / n, if n and d are not 0
mixed number
an integer next to a fraction
consecutive integers
For any integer n, the numbers in the set {n, n + 1, n + 2, n + 3,…}
If x and y are integers and x ≠ 0, then x is a divisor or factor of y if
y = xn for some integer n
quotient
Dividing a positive integer y by a positive integer x, and then rounding down to the nearest nonnegative integer
composite number
integer greater than 1 that’s not prime
Squaring a number greater than 1, or raising it to any power greater than 1, gives
a larger number
Squaring a number between 0 and 1 gives
a smaller number
Number of square roots per positive number
Two, a positive and negative
Number of cube roots per real number
one
The square root of a negative number is
imaginary
Rules of exponentiation
scientific notation
a decimal is written with only one nonzero digit to the decimal point’s left, multiplied by a power of 10.
Formula for the distance an object travels
distance = rate * time
Finding object’s travel speed
distance / time
Work problem
Basic formula is: 1/r + 1/s = 1/h
where r is how long an amount of work takes a certain individual, s is how long that much work takes a different individual and h is how long that much work takes both individuals working at the same time
Least common multiple
the smallest positive integer that is divisible by both a and b
