Exponents & Powers • Topic 1 of 2

Writing Repeated Multiplication as Exponents

An exponent tells how many times to multiply a number (the base) by itself.

5 x 5 x 5 = 5^3 (read as '5 to the power of 3' or '5 cubed')

TermMeaningExample
BaseThe number being multiplied5
ExponentHow many times to multiply3
PowerThe whole expression5^3 = 125

Special cases:

  • a^1 = a (any number to power 1 is itself)
  • a^0 = 1 (any nonzero number to power 0 is 1)
  • 1^n = 1 (one raised to any power is 1)
EXPONENTIAL GROWTH:
  2^1 = 2    **
  2^2 = 4    ****
  2^3 = 8    ********
  2^4 = 16   ****************

LAWS OF EXPONENTS:
  Same base, multiply: a^m x a^n = a^(m+n)
  Same base, divide:   a^m / a^n = a^(m-n)
  Power of power:      (a^m)^n   = a^(m*n)
1
Worked Example
Write 7 x 7 x 7 x 7 using exponents.
Solution7^4 (four 7's multiplied together)
2
Worked Example
Write 10^5 as repeated multiplication.
Solution10 x 10 x 10 x 10 x 10 = 100,000
3
Worked Example
Evaluate 2^6.
Solution2 x 2 x 2 x 2 x 2 x 2 = 64

Key Points

  • Exponent = how many times the base is multiplied by itself
  • Any nonzero number to power 0 = 1
  • a^m x a^n = a^(m+n) when bases are the same
  • (a^m)^n = a^(m*n)
Tap an option to check your answer0 / 4
Q1.$2\times2\times2=$
Explanation: Three $2$s $=2^3$.
Q2.In $5^3$, the number $5$ is the:
Explanation: The base.
Q3.$2^4=$
Explanation: $2\times2\times2\times2$.
Q4.$10^2=$
Explanation: $10\times10$.