Question

In the 1990s, the number of target stores increased from 420 stores to 914 stores. What was the percent increased in the number of Target stores in the 1990s?

Answer 1

Divide 914/420, move the decimal over to the right two places and you'll get approximately 217.5%

EDIT: My mistake, read question wrong.
$914-420 = 494$
$494/420 = 1.17$
117.62% 
Subtract the difference and divide by original number (: Move decimal place over two places.