Ratios And Proportions

By: Eric Long

What are Rates, Ratios and Proportions?

Well:

*Rates are a comparison of two different units

*Ratios are a comparison of two things

*Proportions are 2 equal ratios that compares two things


Now you know!

The 2 Types Of Ratios

They are either:

*Part to Part which is a part of the total number with another part of the total number

Ex: There are 25 students in the class, 12 are boys and 13 are girls


Or


*Part to Whole which is a part of the total number with the total number

Ex: In a classroom, 13 students are girls and there are 25 students in the classroom

Proportionality: To check if it's proportional or non-proportional

How To Set Up Proportions

Read First And Fill In The Numbers And Words/Units Second


Number Word/Unit Number Word/Unit

---------------------------- = ----------------------------

Number Word/Unit Number Word/Unit


Ex: 3 Books 6 Books

------------- = -------------

6 Dollars 12 Dollars


*This is not the only kind of set up! This is only the regular set up and there are many more like the percent proportion, etc

The Types Of Proportions

1.Proportionality: All Numbers Are Given; Regular Set Up But Do It Multiple Times


2.Same 2 Words Twice: 3 Numbers Are Given(Some May Be Inferred); Regular Set Up


3.Constant Of Proportionality And Unit Rate: Amount For One Unit; Regular Set Up But With A Ratio Having A Unit Of One


4.Measurement And Scale Drawing: Changing Between 2 Different Units Or A Picture Of A Smaller Model/Drawing; Regular Set Up But With Different Measurement Units


5.Similar Figures: Same Shape, Different Size; Regular Set Up But Words May Be Long/Short, Length/Width, Etc


6.Percent: If There Is A Percent Or Percent Sign Use The Percent Proportion Which Is Part Over Whole, Percent Over 100