R
Rishtaara
Mathematics · Class 8

Exponents and Powers

Negative exponents, decimal system, and very large-small numbers.

4 sections15–25 min read6 MCQs · 2 examples

Chapter Overview

Class 8 exponents include negative and fractional exponents in introduction, laws for integral exponents, and very large/small numbers in standard scientific notation.

Laws Review

Product

aᵐ × aⁿ = aᵐ⁺ⁿ

Quotient

aᵐ / aⁿ = aᵐ⁻ⁿ

Power of product

(ab)ⁿ = aⁿbⁿ

Negative Exponents

  • a⁻ⁿ = 1/aⁿ
  • (a/b)⁻ⁿ = (b/a)ⁿ

Standard Form

Express 0.000000052 as 5.2 × 10⁻⁸. Used in physics and astronomy.

Solved Examples

Step-by-step solutions — read each step before checking the final answer.

Example 1: Simplify

Simplify (2³)² × 2⁻4.

  1. 12⁶ × 2⁻⁴
  2. 2= 2²

Answer

4

Example 2: Standard Form

Write 0.00056 in standard form.

  1. 15.6 × 10⁻⁴

Answer

5.6 × 10⁻⁴

Key Points to Remember

  • Same base required to combine exponents
  • 10ⁿ shifts decimal n places
  • a⁰ = 1 for a ≠ 0

Exam Tips

  • Write numbers in standard form for clarity
  • Apply laws step by step

Practice MCQs — Exponents and Powers

Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.

Question 1 of 6Score: 0/0

(3²)³ equals: