Unit 2: Comparing and Scaling
Essential Question: How can we analyze proportional relationships and use them to solve problems?
- Solving Proportions and Word Problems Tutorials
- Ratio Word Problems...Cool Interactive using the Bar Model
--> has easy - advanced practice
Ratio: a comparison of two quantities.
These can be expressed with a phrase such as "the ratio of 3 to 5" which means '3 for every 5.'
Ratios can also be written as fractions, or in the notation 3:5
Rate: a comparison of quantities measured in two different units
A rate can be thought of as a direct comparison of two sets (20 cookies for 5 children) or as an average amount (4 cookies per child)
Unit Rate: how much for 1? how much per?
A unit rate is a rate in which the second number, usually the denominator, is 1.
Part to Part Ratio: represents a relationship between one part of a whole and another part of the whole.
For example, in a recipe that calls for 2 cans of juice concentrate and 3 cans of water, the ratios 2:3 and 3:2 are part-to-part ratios.
Part to Whole Ratio: represents a relationship between one part of a whole and the whole
For example, in a recipe that calls for 3 cans of juice concentrate and 3 cans of water, the ratios 2:5 and 3:5 are part-to-whole ratios.
Proportion: and equation stating that two ratios are equal.