Exponent Rules

When powers share the same base, you can combine them without writing out all the factors. Three rules cover almost everything: add exponents to multiply, subtract to divide, and multiply to raise a power to another power. The trick isn't memorizing them — it's seeing why each works and not mixing them up.

Skill

Exponent Rules
  1. What & why

    Every exponent rule comes straight from "an exponent counts factors." Multiply 23×222^3 \times 2^2 and you're just stacking factors of 22:

    23×22=(222)(22)=252^3 \times 2^2 = (2 \cdot 2 \cdot 2)(2 \cdot 2) = 2^5

    Three factors plus two more makes five — so for the same base, multiplying means adding exponents. Dividing cancels factors, so it means subtracting. And a power of a power, like (23)2(2^3)^2, is two copies of 232^3 multiplied — 23×23=262^3 \times 2^3 = 2^6 — so it means multiplying the exponents.

    The catch that trips everyone: these rules combine the exponents, never the bases. 32×34=363^2 \times 3^4 = 3^6, not 969^6 — the base stays 33.

  2. Watch how it works

    Product — add the exponents.

    34×32=34+2=363^4 \times 3^2 = 3^{4+2} = 3^6

    Quotient — subtract the exponents.

    57÷53=573=545^7 \div 5^3 = 5^{7-3} = 5^4

    Power of a power — multiply the exponents.

    (23)2=23×2=26(2^3)^2 = 2^{3 \times 2} = 2^6

    Same base every time; only the exponents combine, by the operation that matches.

  3. Reason through one together

    Decide which rule applies, then combine the exponents — and keep the base. Predict before you check.

    Make a prediction: Write 2³ × 2⁴ as a single power of 2.

  4. Practice until it’s automatic

    Fresh problems, one at a time. Build a streak — the goal is getting them right without stopping to think.

    Streak0/ 5Accuracy0%(0/0)

    Write 3⁴ × 3⁶ as a single power of 3. What is the exponent?

  5. Prove it

    Harder, applied problems at the level you’ll meet on the Regents. Get them all right to earn this skill.

    Question 1 of 8

    Write 3⁴ × 3² as a single power of 3. What is the exponent?

For teachers

Standard, common misconceptions, and suggested use will live here.