Class 6 • Mathematics • Chapter 11
Algebra
Discover how variables and algebraic expressions help us represent unknown quantities and solve simple mathematical problems.
Learn the Basics
Important Concepts
Build your algebra foundation step by step.
Introduction to Variables
Understand how letters can represent unknown or changing numbers.
Constants
Learn about fixed numerical values used in algebraic expressions.
Algebraic Expressions
Understand how numbers, variables and operations form expressions.
Terms and Coefficients
Identify terms and understand the numerical coefficient of a variable.
Using Variables
Use variables to represent unknown quantities in everyday situations.
Simple Equations
Learn how simple equations can represent mathematical relationships.
Understand with Examples
Worked Examples
Variable
Example
x + 5
x represents an unknown number.
Expression
Example
3a + 7
3a and 7 are terms.
Finding a Value
If a = 4
3a + 7
= 3(4) + 7 = 19
Visual Learning
Understanding a Variable
A variable is a symbol, usually a letter, that can represent a number.
Variable
x
Example Value
5
Expression
x + 2
Quick Notes
Remember These Points
- • A variable is a letter or symbol used to represent a number.
- • A constant has a fixed numerical value.
- • An algebraic expression may contain numbers, variables and operations.
- • In 5x, 5 is the coefficient of x.
- • Substituting a value for a variable allows us to evaluate an expression.
Practice
Practice Questions
If x = 5, find the value of x + 7.
Write an algebraic expression for '5 more than x'.
Identify the variable and constant in 7y + 3.
Write an expression for the perimeter of a square with side x.
If a = 10, find the value of 3a.
Find the value of x if x + 4 = 9.
Test Yourself
Revise variables, expressions and simple equations before taking the quiz.