Take a percent of the wrong reference amount (e.g., new price vs. original).
An error-pattern drill: practice spotting and avoiding this specific SHSAT trap.
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A shirt costs 80 dollars after a 20% discount. What was the original price? Many students add 20% of 80 back: \(80 + 16 = 96\) dollars. That is wrong. The 20% was taken from the original price, not from 80. The sale price is 80% of the original, so the original is \(80 \div 0.8 = 100\) dollars.
The trap works because 80 is the only price in the question, so it feels like the base. But a percent is always "of" something, and that something can be a number you do not know yet.
Check habits:
If \(\$44.80\) is what's left after a 36% discount, it is 64% of the original: original \(= \$44.80 \div (64/100) = \$70.00\). (Adding 36% of the sale price back (\(\$44.80 \times 1.36\)) gives about $60.93. Dividing by 36% instead of 64% (\(\$44.80 \div 0.36\)) gives about $124.44. Taking 36% off the sale price again (\(\$44.80 \times 0.64\)) gives about $28.67.) The original price was $70.00.
Percent more \(= (A - B) \div B \times 100 = (369 - 225) \div 225 \times 100 = 64\%\). (Dividing by Malik's score instead of Yuki's (\(144 \div 369 \times 100\)) gives about 39.02%. Finding what percent 369 is of 225 gives 164%. Writing the 144-point difference as a percent gives 144%.) Malik's score is 64% greater than Yuki's.