Learn on PengiThe Art of Problem Solving: Prealgebra (AMC 8)Chapter 2: Exponents

Lesson 3: Zero as an Exponent

In this Grade 4 lesson from The Art of Problem Solving: Prealgebra (AMC 8), students learn why any nonzero number raised to the power of zero equals 1, using two approaches: identifying a halving pattern in descending powers of 2 and applying the quotient of powers rule. Students then practice evaluating expressions containing zero exponents, including cases where the base is a variable or a compound expression.

Section 1

Zero as an Exponent

Property

a0=1a^0 = 1, if a0a \neq 0

This definition is based on the second law of exponents. For any non-zero number aa, the quotient anan\frac{a^n}{a^n} is equal to 1. Using the law of exponents, we can also write anan=ann=a0\frac{a^n}{a^n} = a^{n-n} = a^0. Therefore, it is logical to define a0a^0 as 1.

Examples

  • For a positive integer, 80=18^0 = 1.
  • For a negative integer, (55)0=1(-55)^0 = 1.
  • For an algebraic term where variables are non-zero, (2ab2)0=1(2ab^2)^0 = 1.

Section 2

Zero Exponent

Property

If aa is a non-zero number, then a0=1a^0 = 1. Any nonzero number raised to the zero power is 1. In this text, we assume any variable that we raise to the zero power is not zero.

Examples

  • Any non-zero number to the zero power is 1, so 150=115^0 = 1.
  • For any non-zero variable pp, it is true that p0=1p^0 = 1.

Book overview

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Chapter 2: Exponents

  1. Lesson 1

    Lesson 1: Squares

  2. Lesson 2

    Lesson 2: Higher Exponents

  3. Lesson 3Current

    Lesson 3: Zero as an Exponent

  4. Lesson 4

    Lesson 4: Negative Exponents

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

Zero as an Exponent

Property

a0=1a^0 = 1, if a0a \neq 0

This definition is based on the second law of exponents. For any non-zero number aa, the quotient anan\frac{a^n}{a^n} is equal to 1. Using the law of exponents, we can also write anan=ann=a0\frac{a^n}{a^n} = a^{n-n} = a^0. Therefore, it is logical to define a0a^0 as 1.

Examples

  • For a positive integer, 80=18^0 = 1.
  • For a negative integer, (55)0=1(-55)^0 = 1.
  • For an algebraic term where variables are non-zero, (2ab2)0=1(2ab^2)^0 = 1.

Section 2

Zero Exponent

Property

If aa is a non-zero number, then a0=1a^0 = 1. Any nonzero number raised to the zero power is 1. In this text, we assume any variable that we raise to the zero power is not zero.

Examples

  • Any non-zero number to the zero power is 1, so 150=115^0 = 1.
  • For any non-zero variable pp, it is true that p0=1p^0 = 1.

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 2: Exponents

  1. Lesson 1

    Lesson 1: Squares

  2. Lesson 2

    Lesson 2: Higher Exponents

  3. Lesson 3Current

    Lesson 3: Zero as an Exponent

  4. Lesson 4

    Lesson 4: Negative Exponents