This document provides an overview of ratios, proportions, and percentages. It defines a ratio as a comparison of numbers expressed as a fraction. Proportions are statements that two ratios are equal. To solve proportions, terms are cross multiplied. Percentages express a number out of 100. To convert between fractions, decimals, and percentages, the decimal is moved or the number is divided by the total. Percent problems involve finding a percentage of a given number.