Topic 3 Percents

Interest: the amount charged or added to a loan or bank account

Interest Rate: a percent charged or added to a loan or bank account

Markdown: a percent decrease for a sale

Markup: a percent increase for a sale

Percent: a ratio with a denominator of 100

Percent Change: the ratio: (change) / (original value) expressed as a percent

Percent Equation: (part) = (percent)(whole)

Percent Error: the ratio: (difference) / (true value) expressed as a percent

Principal: the starting value of a loan or bank account

Proportion: a relationship of equal ratios. Example: 1/2 = 5/10, or a/b = p/r

Rate: another word for ratio. The word "rate" is typically used when describing change.

Ratio: a comparison of numbers by division. Examples: 3/4, 3:4, 3 to 4

Simple Interest: interest that uses an unchanging principal. B = Prt + P