Exponents with decimal and fractional bases
Key Notes :
๐ Exponents with Decimal and Fractional Bases
| ๐น What is an Exponent? |
An exponent shows how many times a number (called the base) is multiplied by itself.
๐ Example:
32=3ร3=9
| ๐น Decimal Bases |
A decimal base is a number that contains a decimal point.
When a decimal base is raised to a power, we multiply the base by itself as many times as the exponent shows.
โจ Examples:
- (0.2)2=0.2ร0.2=0.04
- (0.5)3=0.5ร0.5ร0.5=0.125
๐ Tip: The result becomes smaller as you multiply decimals less than 1.
| ๐น Fractional Bases |
A fractional base is a number written in the form a/bโ.
When raised to a power, both the numerator and the denominator are raised to that power.
โจ Examples:
- (2/3)2=22/32=4/9
- (1/4)3=13/43=1/64
| ๐น Negative Exponents |
A negative exponent means we take the reciprocal of the base and make the exponent positive.
โจ Examples:
- (0.2)โ1=1/0.2=5
- (3/4)โ2=(4/3)2=16/9
| ๐น Zero Exponent Rule |
Any non-zero number raised to the power of 0 equals 1.
โจ Examples:
- (0.5)0=1
- (2/3)0=1
| ๐น Comparing Decimal and Fractional Bases |
- Both decimals and fractions less than 1 become smaller as the exponent increases.
- Example: (0.5)2=0.25 and (1/2)2=1/4โ, which are the same value.
| ๐น Real-Life Applications ๐ก |
- Calculating interest rates and growth/decay in financial problems.
- Finding areas and volumes when measurements are in decimals or fractions.
- Used in scientific notation for very small numbers (like (1.2ร10โ3)2).
| ๐ง Quick Practice |
- (0.3)3=?
- (2/5)2=?
- (0.4)โ2=?
- (3/4)0=?
Learn with an example
Evaluate. Write your answer as a fraction or whole number.
(1/2)4 =____
(1/2)4 = 1/2 ร 1/2 ร 1/2 ร 1/2
= 1/2.2.2.2
= 1/16
Evaluate. Write your answer as a decimal or whole number.
(0.03)4 =____
The base is 0.03 and the exponent is 4. Use 0.03 as a factor 4 times.
| (0.03)4 | = | 0.03 ยท 0.03 ยท 0.03 ยท 0.03 |
= 0.00000081
Evaluate. Write your answer as a decimal or whole number.
(0.01)4 =_______
The base is 0.01 and the exponent is 4. Use 0.01 as a factor 4 times.
(0.01)4 = 0.01 ยท 0.01 ยท 0.01 ยท 0.01
= 0.00000001
Let’s practice!๐๏ธ

