5-B-1:  The Magic of Proportions

Cleaning the bathroom is my very least favorite chore.  I leave it for Saturday morning but all I want to do is get to family time.  We have 3 bathrooms in our house.  If it takes me 30 minutes to clean 1 bathroom, how long will it take to clean 3?

Let’s set up the proportion like so…..

          1/30   =    3/?

First I ask myself, how many times does 1 go into 3? Answer: 3 times.

Then I take 3 and multiply it by 30.  Answer: 90.

          1/3     =     3/90

If it takes 30 minutes to clean one bathroom, it will take 90 minutes to clean 3 bathrooms.  So after 1 hour and 30 minutes I am free to play!

*****************************************************************

My sons’ soccer tournament is today.  His coach said it is 125 miles away.  I drive very slow, 50 miles per hour.  We need to be there by 10:00 a.m., what time do we have to leave?

Let’s set up the proportion like so….

          1 hour/50 miles     =     ?/125 miles

First I ask myself, how many times does 50 go into 125? Answer:  2.5 times.  Then I take 2.5 and multiply it by 1.  Answer:  2.5

          1 hour/50 miles     =     2.5 hours/125 miles

It will take 2 ½ hours to get to the soccer game.  Since we need to be there by 10:00, we will need to leave at 7:30.