Given the original selling price of DVD player as $179.30 and the new sale price to be $144.77, the the first step in finding the percent markdown is to take the difference between the original selling price and the sale price to give $179.30 - $144.77 = $34.53
Percent markdown = original selling price- new sale price/original selling price × 100%
Keep doing each step manually, and see where it slips up:
−7.9+8.2−3.4+2.1=−1
−7.9+8.2+(−3.4)+2.1=−1
−7.9+(−3.4)+8.2+2.1=−1
(−7.9+(−3.4))+(8.2+2.1)=−1
−11.3+10.3=−1
