Verification Strategies

A few seconds of checking prevents the most common, most painful SAT errors.

Most wrong answers on the SAT are not from not knowing the math — they are from a small slip or from answering the wrong question. Build three quick checks into every problem you have time for.

1. Plug it back in. Substitute your answer into the original equation.If both sides match, the value is right.
2. Check the size and sign. Is the answer reasonable?A length cannot be negative; a probability cannot exceed 1.
3. Re-read the question. Did it ask for x, or for 2x + 1?The classic trap: solving correctly, then bubbling the wrong quantity.

For word problems, restate the answer in the story: “so the train takes 3 hours” — does that fit? The calculator makes plug-back-in almost free: type the original expression with your answer in place and confirm it lands on the target.