A price is decreased from £800 to £640. Calculate the percentage change.

There is a decrease of 20% from ÂŁ800 to ÂŁ640.

A change from 800 to 640 represents a negative change (decrease) of - 20% Using the formula:

Percent change = [ (800 - 640) / 800] x 100 = - 20 % (decrease)

800 is the old value and 640 is the new value. In this case we have a negative change (decrease) of - 20 percent because the new value is smaller than the old value.