Logarithms
ICSE · Class 9 · Mathematics
Summary of Logarithms for ICSE Class 9 Mathematics. Key concepts, important points, and chapter overview.
Interactive on Super Tutor
Studying Logarithms? Get the full interactive chapter.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for chapter summary and more.
1,000+ Class 9 students started this chapter today

Learn better with visuals Super Tutor has hundreds of illustrations like this across every chapter — all free to try.
Get startedOverview
Logarithms are mathematical tools that make complex calculations involving powers and roots much simpler. They represent the inverse relationship of exponential functions. If a^b = c, then log_a c = b. This chapter introduces the fundamental concept of logarithms, their properties, and various laws
Key Concepts
If a^b = c (where
If a^b = c (where a ≠ 1), then b is called the logarithm of c at base a, written as log_a c = b. This means logarithm answers the question: 'To what p
Any exponential equation a^b = c
Any exponential equation a^b = c can be written as log_a c = b (logarithmic form) and vice versa. For example: 2^3 = 8 ⟺ log_2 8 = 3
log_a(m × n) = log_a m
log_a(m × n) = log_a m + log_a n. The logarithm of a product equals the sum of logarithms of individual factors
log_a(m/n) = log_a m
log_a(m/n) = log_a m - log_a n. The logarithm of a quotient equals the difference of logarithms
log_a(m^n) = n × log_a m
log_a(m^n) = n × log_a m. The logarithm of a power equals the exponent multiplied by the logarithm of the base number
Learning Objectives
- Understand the definition and basic concept of logarithms
- Convert between exponential form and logarithmic form
- Apply the three fundamental laws of logarithms (Product, Quotient, and Power laws)
- Solve equations involving logarithms
- Express complex expressions using logarithmic expansions
Frequently Asked Questions
What are the important topics in Logarithms for ICSE Class 9 Mathematics?
How to score full marks in Logarithms — ICSE Class 9 Mathematics?
Sources & Official References
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
More resources for Logarithms
Important Questions
Practice with board exam-style questions
Syllabus
What topics to cover
Revision Notes
Key points for last-minute revision
Study Plan
Step-by-step plan to ace this chapter
Flashcards
Quick-fire cards for active recall
Formula Sheet
All formulas in one place
Practice Quiz
Test yourself with a quick quiz
Concept Maps
See how topics connect visually
For serious students
Get the full Logarithms chapter — for free.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for ICSE Class 9 Mathematics.