8th grade · Math · Unit 12 of 17
Exponent Rules
Add, subtract, multiply exponents
What your child practices
Properties of integer exponents: multiplying and dividing powers with the same base, a power of a power, zero exponents and negative exponents.
Alaska content standards learning standard: 8.EE.1 · applying the properties of integer exponents to write equivalent expressions
How we explain it
Children can open this short lesson before they practice.
- Multiply powers with the same base: add the exponents.
- Divide: subtract the exponents. Power of a power: multiply them.
- a⁰ = 1, and a⁻ⁿ = 1/aⁿ.
Example: Simplify 2³ × 2⁴. Same base, so add: 3 + 4 = 7. Answer: 2⁷
Exponent Rules in Alaska
In the Alaska content standards, this is unit 12 of 17 in 8th grade Math, after Congruent Shapes and before Systems of Equations.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Alaska Department of Education and Early Development
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
What is 3⁻¹?
- 3
- −3
- 1/3
- −1/3
1/3
Hint: A negative exponent means one over: 3⁻¹ = 1/3¹ = 1/3.
Question 2
What is the value of 5³ × 5⁻²?
- 125
- 3125
- 25
- 5
5
Hint: Add the exponents: 3 + (-2) = 1. 5¹ = 5.
Question 3
Simplify 3⁵ × 3⁶.
- 3¹¹
- 3³⁰
- 9¹¹
- 3¹
3¹¹
Hint: When you multiply powers with the same base, add the exponents.
Question 4
Simplify 7⁹ ÷ 7⁶.
- 7¹⁵
- 7³
- 7²
- 1³
7³
Hint: When you divide powers with the same base, subtract the exponents.
Question 5
Simplify (3⁴)⁵.
- 3²¹
- 3²⁰
- 15⁴
- 3⁹
3²⁰
Hint: A power of a power: multiply the exponents.
Question 6
Simplify (8³)².
- 8⁵
- 16³
- 8⁷
- 8⁶
8⁶
Hint: A power of a power: multiply the exponents.