Algebra
Basic

Zero Exponent

Any nonzero number to the power zero is one.

Formula

a0=1,  a≠0a^0 = 1, \; a\neq 0

Variables

aBase

Example

99^0 = 1

How it works

The zero exponent rule says that any nonzero base raised to the power 0 equals 1. This fits the pattern of dividing by the same number repeatedly: for example, 5^3 = 125, 5^2 = 25, 5^1 = 5, and 5^0 must be 1 so the pattern keeps working as each step divides by 5. The rule does not apply to 0^0, because zero cannot be used as the base here.

When to use it

Use this rule when simplifying expressions with exponents, especially in algebra and scientific notation. It also helps when reducing formulas or checking patterns in powers of the same number.

Worked example, step by step

Evaluate 7^0 Step 1: Identify the base: a = 7 Step 2: Apply the zero exponent rule: a^0 = 1 for any nonzero a Step 3: So, 7^0 = 1 Final answer: 1

Common mistakes to avoid

  • Thinking that 0 means the answer should be 0
  • Using the rule on 0^0, which is not allowed here
  • Confusing the zero exponent rule with the power of one rule, a^1 = a

Did You Know?

Any non-zero number to the power zero equals 1, a convention that keeps the laws of exponents consistent.

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Reviewed & maintained by the FormulaWon editorial teamLast reviewed September 2026