Suppose you ride your bicycle to the library traveling at 0.5 km/min. It takes you 25 minutes to get to the library. How far did you travel?

If you cover 0.5 km every minute, and keep it up for 25 minutes,

then you will cover

0.5 + 0.5 + 0.5 + 0.5 + 0.5 +

0.5 + 0.5 + 0.5 + 0.5 + 0.5 +

0.5 + 0.5 + 0.5 + 0.5 + 0.5 +

0.5 + 0.5 + 0.5 + 0.5 + 0.5 +

0.5 + 0.5 + 0.5 + 0.5 + 0.5 = 12.5 km.

An easier way to write the same thing is

(25) times (0.5 km) = 12.5 km.