Evaluate exponents
key notes :
🔹 What is an Exponent? |
- An exponent tells us how many times a number (the base) is multiplied by itself.
- General form: an=a×a×a…×a (n times)
- a → base
- n → exponent (or power)
- Example: 34=3×3×3×3=81
🔹 Important Rules of Exponents |
Product of Powers Rule:
- am×an=am+n
- Example: 23×24=27=128
Quotient of Powers Rule:
- am/an=am−n (a≠0)
- Example: 56/52=54=625
Power of a Power Rule:
- (am)n=am⋅n
- Example: (32)4=38=6561
Power of a Product Rule:
- (ab)n=an.bn
- Example: (2×3)4=24×34=16×81=1296
Power of a Quotient Rule:
- (a/b)n=an/bn (b≠0)
- Example: (4/5)2=16/25
Zero Exponent Rule:
- a0=1 (a≠0)
- Example: 70=1
Negative Exponent Rule:
- a−n=1/an (a≠0)
- Example: 2−3=1/23=1/8
🔹 Evaluating Exponents (Examples) |
- 25=2×2×2×2×2=32
- (53)2=56=15625
- 74/72=74−2=72=49
- 10−2=1/102=1/100
- (3×2)3=33×23=27×8=216
🔹 Common Mistakes to Avoid |
am+an≠am+n
(a+b)2≠a2+b2 (it is a2+2ab+b2)
Negative sign matters:
- (−2)4=16
- −24=−16
🔹 Real-Life Applications of Exponents |
- Scientific notation (large and small numbers).
- Growth and decay problems (population growth, bacteria growth, radioactive decay).
- Area and volume calculations.
- Computer science (binary numbers and memory size like KB, MB, GB).
✅ Summary: |
- Exponents are repeated multiplication.
- Learn and apply exponent rules correctly.
- Be careful with signs, brackets, and negative powers.
Learn with an example
✈️ Evaluate.
92 =
- The base is 9 and the exponent is 2. Use 9 as a factor 2 times.
- 92 = 9 · 9
- = 81
✈️ Evaluate.
43 =
- The base is 4 and the exponent is 3. Use 4 as a factor 3 times.
- 43 = 4 · 4 · 4
- = 64
✈️ Evaluate.
62 =
- The base is 6 and the exponent is 2. Use 6 as a factor 2 times.
- 62 = 6 · 6
- = 36
Let’s practice!🖊️