Subject: Scale factors vs. ratios
Name: Maggie
Who are you: Student

I have a BIG math test coming up, and it's about scale factors and ratios, but i don't understand them at all. How can you tell the difference between scale factors and ratios? and How are they used in the everyday world?


Hi Maggie,

I went to a store on the web where they sell model airplane kits and they had a kit with the scale of 1/48. That means that if I make the model then the actual airplane will be 48 times as long as the model. 1/48 is the scale factor. You also see scale factors on maps and blueprints.

Lets look at another example. There was a vote by students to decide whether to have a Christmas party this year. After the vote the results were reported by saying "The number of yes votes and the number of no votes were in the ratio of 3:2." This means that you can arrange the ballots in piles of 5 where in each pile there are 3 yes votes and 2 no votes. Thus three-fifths of the votes were yes and two-fifths of the votes were no. Can you say this in terms of a scale factor? Can you fill in the blank in the sentence "There were ____ times as many yes votes as no votes." Three-fifths of the votes were yes and two-fifths were no so I am asking

find f if 2/5 x f = 3/5

Solving for f gives f = 3/2 so the scale factor is 1.5. There were one and a half times as many yes votes as no votes.

I hope this helps and good luck on the test,