You can put this solution on YOUR website! First, find the amount of decrease by subtracting 100 from 290: 290 - 100 = 190
Then, put that number over the initial value and reduce to decimal form:
To convert from decimal form to percent, move the decimal over to the right two places: 0.655 = 65.5%
Thus, the percent of decrease from 290 to 100 is 65.5%