Ratios & Proportions
Every lesson explains the concept, works through examples, and gives you practice problems with full solutions. Work through them in order, or jump to the topic you need.
6 lessons
- What Is a Ratio? Comparing Two QuantitiesWhat a ratio means, the three ways to write one, the difference between part-to-part and part-to-whole ratios, and why the order of the numbers matters.
- Equivalent Ratios and Ratio TablesHow to find equivalent ratios by multiplying or dividing both parts, how to build and read a ratio table, and how to fill in a missing value.
- Unit Rates: Finding the Price of OneWhat a unit rate is, how to find one by dividing, how to use unit price to compare two deals, and the difference between a rate and a ratio.
- Converting Units with RatiosHow to convert between units by multiplying by a ratio equal to 1, why the unwanted unit cancels, and how to decide which way up the conversion factor goes.
- Solving Proportions and Cross MultiplicationWhat a proportion is, how to solve one by cross multiplying, why cross multiplication works, and how to check whether two ratios form a proportion.
- Proportional Relationships and the Constant of ProportionalityHow to tell whether two quantities are proportional from a table, graph or equation, find the constant of proportionality, and why the graph passes through the origin.