How to Solve Exponents and Powers — Step by Step Guide

Laws of exponents, scientific notation, and simplification. This guide covers Class 7 to 8.

Step-by-Step Method

  1. 1

    Understand the notation: a^n means a multiplied by itself n times.

  2. 2

    Key laws: a^m × a^n = a^(m+n), a^m ÷ a^n = a^(m-n), (a^m)^n = a^(mn).

  3. 3

    Special cases: a^0 = 1 (for a ≠ 0), a^(-n) = 1/a^n.

  4. 4

    To write in standard form (scientific notation): express as a number between 1 and 10 multiplied by a power of 10.

  5. 5

    When simplifying, apply the laws step by step and combine like bases.

Worked Example

Problem: Simplify 2³ × 2⁵ ÷ 2⁴

Solution: 2³ × 2⁵ = 2⁸. 2⁸ ÷ 2⁴ = 2⁴ = 16.

Common Mistakes to Avoid

  • Multiplying the base along with the exponent: 2³ × 2⁴ ≠ 4⁷, it equals 2⁷.

  • Confusing (ab)^n with a^n × b — it should be a^n × b^n.

  • Forgetting that a^0 = 1, not 0.

  • Incorrect handling of negative exponents.

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Frequently Asked Questions

How do I solve Exponents and Powers problems?
Understand the notation: a^n means a multiplied by itself n times. Key laws: a^m × a^n = a^(m+n), a^m ÷ a^n = a^(m-n), (a^m)^n = a^(mn).
What are common mistakes in Exponents and Powers?
Multiplying the base along with the exponent: 2³ × 2⁴ ≠ 4⁷, it equals 2⁷. Confusing (ab)^n with a^n × b — it should be a^n × b^n.
Which class covers Exponents and Powers?
Exponents and Powers is typically taught in Class 7, 8. SparkEd has free practice for all these grades.
Where can I practise Exponents and Powers for free?
SparkEd offers free chapter-wise practice for Exponents and Powers aligned to CBSE, ICSE, and IB curricula. Visit sparkedmaths.com to start.

SparkEd Maths — sparked.coms@gmail.com — www.sparkedmaths.com