Evaluate negative exponents
Key Notes :
π Evaluate Negative Exponents π
| πΉ What Are Exponents? |
An exponent shows how many times a number (called the base) is multiplied by itself.
- π Example: 23=2Γ2Γ2=8
| πΉ What Are Negative Exponents? |
A negative exponent means take the reciprocal (flip the base) and make the exponent positive.
π Example:
- 2β3=1/23=1/8
π§ Rule:
aβn=1/an (where aβ 0)
| πΉ Examples |
- 5β2=1/52=1/25
- 10β1=1/101=1/10
- (2/3)β2=(3/2)2=9/4β
| πΉ Important Properties of Exponents |
1. Product of powers:
amΓan=am+n
2. Quotient of powers:
am/an=amβn
3. Power of a power:
(am)n=amΓn
4. Zero exponent:
a0=1 (where aβ 0)
5. Negative exponent:
aβn=1/an
| πΉ Real-Life Application π |
Negative exponents are used in:
- Scientific notation for small numbers:
2.5Γ10β3=0.0025 - Physics and Chemistry to represent very small quantities like charge, mass, or wavelength.
| πΉ Quick Tip π‘ |
Always remember:
- Negative exponents donβt make the value negative,
- they just flip the fraction!
| π§© Practice Problems |
- 3β2=?
- 1/4β3=?
- (52)β1=?
- 2β4Γ23=?
- (1/2)β2=?
Learn with an example
Write the expression as a fraction with a positive exponent. Do not evaluate the expression.
9-2
The base has a negative exponent, β2. You can rewrite the expression as a fraction with a numerator of 1 and a positive exponent, 2, in the denominator.

Write the expression as a whole number with a negative exponent. Do not evaluate the expression.
1/73
There is a positive exponent, 3, in the denominator. You can rewrite the expression with an exponent of β3 instead.

Evaluate. Write your answer as a fraction or whole number without exponents.
3β3 =

Let’s practice!ποΈ

