Ratios Rates Proportional Relationships and Units
Ratios, rates, proportions, unit conversions, and density formulas
Questions about converting units, applying rates, setting up proportions, and working with density formulas.
Why this matters
There are five question types: unit conversions, rate applications, proportions, density formulas, and algebraic ratios. Each one has a different setup.
The five patterns
Unit Conversion
Convert a quantity from one unit to another. Multiply by conversion factors so unwanted units cancel out.
›Rate Application
Apply a rate (miles per hour, cost per item) to find a total, a unit rate, or a comparison between two rates.
›Proportion Solving
Two ratios are equal. Set up the proportion, cross-multiply, and solve for the missing value.
›Density Formula
Use density = quantity ÷ space (mass/volume, population/area). Plug in two values, solve for the third.
›Variable Ratios
Set up algebraic expressions for proportional relationships. The ratio involves variables, not just numbers.