Negative exponent
SAT glossary · Course Foundations
Definition
A negative exponent means reciprocal, handled last: 8^-2/3 is 1/(8^2/3)=1/4. It never makes a positive base negative; it flips it into a denominator. The option -4 — reading the negative exponent as a negative sign — is the single most common exponent error and it is on every test.
Negative exponent in plain English
A negative exponent doesn't make a number negative — it means 'take the reciprocal' (flip it into a fraction), and you handle it LAST, after dealing with any other operations. So 8^-2/3 means: first find 8^2/3 (which comes out to 4), and THEN flip it into a fraction, giving 1/4 — never a negative number. This is genuinely the single most common exponent mistake on the whole test: seeing a negative sign in the exponent and instinctively making the final ANSWER negative (like guessing -4), when a negative exponent has nothing to do with the sign of the result at all — it only controls whether the number ends up as a fraction.
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