Introduction to Exponents

Learn what exponents are and how they simplify repeated multiplication.

Intermediate25 minLesson

Definition

An exponent tells you how many times to multiply a number by itself.
In the expression :
  • is the base (the number being multiplied)
  • is the exponent (how many times to multiply)
We read as "two to the fifth power" or "two to the power of five."
Special names:
  • is called "n squared" (like the area of a square)
  • is called "n cubed" (like the volume of a cube)

Try it now

What does mean?

Worked Examples

Calculate

1

Identify base and exponent

Base = 3, Exponent = 4Multiply 3 by itself 4 times

2

Write out the multiplication

Four 3s multiplied

3

Multiply step by step

, then , then 81

Common Mistakes

Multiplying base by exponent:

Why it's wrong: This confuses exponentiation with multiplication. The exponent tells you how many times to multiply, not what to add.

Correct: , not

Thinking

Why it's wrong: Exponents don't work like regular addition. You can't split them this way.

Correct: , while . These are different!

Writing as and thinking they're different

Why it's wrong: Any number to the power of 1 equals itself:

Correct: and are the same value, just written differently

Interactive Visual

2^3 = 8
3

See how powers of a number grow on the number line. Change the base and exponent.

Factor Tree

Number:
Composite
Prime

Enter a number to see its factor tree and prime factorization.

Interactive Sandbox

Expression Calculator

Try these:

History

No calculations yet

Practice Problems

17 problems
Problem 1 of 17
Easy

What does mean?

Why It Matters

Exponents are a powerful shorthand that appears everywhere:
  • Computer storage: Memory is measured in powers of 2 (1 KB = bytes)
  • Science: Atoms are incredibly small ( meters)
  • Finance: Compound interest grows exponentially
  • Biology: Bacteria can double every hour ( = 16 million in one day!)
Without exponents, writing (one trillion) would require 12 zeros!

Real World Applications

Computer Memory

Computer memory is measured in powers of 2 because computers use binary (0s and 1s).

Example:

1 Kilobyte = = 1,024 bytes. 1 Megabyte = = 1,048,576 bytes.

1Try It Yourself

A small text file is about bytes (4 KB).

How many bytes is that exactly?

Step 1: Write the mathematical expression

Calculate :

Bacterial Growth

Bacteria multiply by splitting in two. Each hour, the population doubles.

Example:

Starting with 1 bacterium, after 10 hours you have = 1,024 bacteria!

2Try It Yourself

You start with 1 bacterium that doubles every hour.

How many bacteria after 8 hours?

Step 1: Write the mathematical expression

Calculate :

Area and Volume

Exponents naturally appear in geometry: area uses squared, volume uses cubed.

Example:

A square with side 7 cm has area square cm. A cube with side 4 cm has volume cubic cm.

3Try It Yourself

You have a cube-shaped box with sides of 5 cm.

What is the volume of the box?

Step 1: Write the mathematical expression

Calculate :

Key Takeaways

  • 1An exponent tells how many times to multiply a base by itself: (n times)
  • 2The base is the number being multiplied; the exponent is how many times
  • 3 is "n squared" and is "n cubed"
  • 4Powers of 10 are especially useful: is 1 followed by n zeros
  • 5Any number to the power of 1 equals itself:

Frequently Asked Questions

Any non-zero number to the power of 0 equals 1. For example, , . This will be covered in detail in a future lesson!
Any non-zero number to the power of 0 equals 1. For example, , . This will be covered in detail in a future lesson!
'Squared' comes from calculating the area of a square (side times side). 'Cubed' comes from calculating the volume of a cube (side times side times side).
No! (two multiplied three times) but (three multiplied two times). The order matters!

Glossary

Exponent
The small number written above and to the right that shows how many times to multiply the base by itself
Base
The number that gets multiplied by itself in exponential notation
Power
The result of raising a base to an exponent (e.g., 8 is a power of 2)
Squared
Raised to the power of 2 (multiplied by itself once)
Cubed
Raised to the power of 3 (multiplied by itself twice)

More in This Topic