Core
Exponents and Powers: Core
Core
Exponents and Powers (NCERT Ch. 13)
What you'll learn
- Express numbers using exponential notation (base and exponent).
- Apply the laws of exponents: product rule, quotient rule, power rule, zero exponent.
- Express large numbers in standard form (scientific notation).
Key concepts
- aᵐ x aⁿ = aᵐ⁺ⁿ (product rule — same base, add exponents).
- aᵐ ÷ aⁿ = aᵐ⁻ⁿ (quotient rule — same base, subtract exponents).
- (aᵐ)ⁿ = aᵐⁿ (power rule — multiply exponents).
- a⁰ = 1 (any nonzero base raised to power 0 equals 1).
- Standard form: a number written as k x 10ⁿ, where 1 ≤ k < 10.
Worked example
Simplify: 2³ x 2⁴
Same base, add exponents: 2³ x 2⁴ = 2^(3+4) = 2⁷ = 128
Common mistakes
- Adding exponents when the bases are different (only valid for the same base).
- Multiplying the base by the exponent instead of using repeated multiplication (2³ = 2x2x2 = 8, NOT 2x3=6).
- Forgetting a⁰ = 1 (not 0).
Quick check
- Simplify: 5⁶ ÷ 5².
- Write 45,000 in standard form.
Open the Practice tab for graded questions on Exponents and Powers (NCERT Ch. 13).
Key Takeaways (TL;DR)
- What you'll learn
- Key concepts
- Worked example
- Common mistakes
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