A dollar bill is 15.6 cm long. If 200 dollar bills were laid end to end, how many meters long would the line be?

31.2 m

First, you would multiply 15.6 by 200 because you have 200 dollar bills that are each 15.6cm long. The resulting length is 3,120 cm. Now, you have to convert cm to meters because the answer was asked to be in meters. Since 1 meter equals 100 cm, you divide 3,120 cm by 100 to get 31.2 meters.

The proper way to convert is by using , which comes in handy for more complicated conversions, but this one is simple enough where you don't have to use it. The dimensional analysis equation would be set up like this:

3,120cm x ##(1m)/(100cm)## = ##(3,120m)/100## = 31.2m

Notice how the cm cancel out and the only unit left is m; that is how you know you've set up the equation correctly.