Many problems are solved using ratios, but there are many ways to find the solution to a ratio problem.   Two of the methods include:

  • using a unit rate
  • using a proportion

A proportion is simply when an equivalent ratio is setup (using either a fraction or ratio notation) and then an equivalent ratio is made.  There are a couple of different ways to find the missing value in your equivalent ratio.

Watch the 4 videos on proportional reasoning:

  1. Introduction to proportions
  2. Solving a problem using either proportions or unit rate
  3. How the capture-release-recapture method of estimating natural populations is actually proportional reasoning
  4. Example using pricing/unit pricing.

4 video playlist

Assignment:

Things you should know how to do after today:

  • use proportions or unit rates to solve proportional situations (involving ratios)