What is an algebraic expression as defined in NCERT Class 7 Maths Chapter 4?

An algebraic expression is a mathematical statement made up of numbers, variables (letters representing unknown values), and arithmetic operations such as addition, subtraction, multiplication, and division. For example, x+5 or 3y−7 are algebraic expressions.

What is the difference between a variable and a constant?

In algebraic expressions, a variable is a letter that represents a quantity whose value can change or is unknown (e.g., x,y,z). A constant is a numerical value that is fixed and does not change (e.g., 5,−10,0.7).

How do you evaluate an algebraic expression?

To evaluate an algebraic expression, you substitute the given numerical value(s) for the variable(s) in the expression and then perform the arithmetic operations to find the final numerical value of the expression.

What are "like terms" and why are they important in simplifying expressions?

Like terms are terms in an algebraic expression that have the exact same variables raised to the exact same powers (e.g., 4x and 7x; 2xy and −5xy). They are important because only like terms can be combined (added or subtracted) to simplify an expression, making it shorter and easier to work with.

Is your child in Class 5-10?

Give them an early start to success—register for TALLENTEX now!

NCERT Solutions

Class 7

Maths

Chapter 4 Expressions Using Letter-Numbers

NCERT Solutions Class 7 Maths Chapter 4 Expressions Using Letter-Numbers

NCERT Solutions Class 7 Maths Chapter 4: Expressions Using Letter-Numbers introduces students to the basics of algebra. In this chapter, students learn how letters (like x or y) can be used to represent numbers. These letter-number combinations, called expressions, help us solve problems in a smarter and quicker way. Students also learn how to form expressions from real-life situations and how to simplify them.

These NCERT Solutions break down each question with simple explanations and step-by-step answers. They are perfect for Class 7 students who are starting to explore letter-based maths. With practice and guidance from NCERT Solutions, students can become comfortable using variables and learn to form and simplify expressions with ease.

1.0NCERT Solutions Class 7 Maths Chapter 4 Expressions Using Letter-Numbers – Download PDF

You can now download a free PDF of NCERT Solutions Class 7 Maths Chapter 4 from ALLEN, prepared by our expert faculty.

NCERT Solutions for Class 7 Maths Chapter 4: Expressions Using Letter-Numbers

Available Soon

2.0Key Concepts in Chapter 4: Expressions Using Letter-Numbers

1. Introduction to Letters as Numbers

Letters like x, y, z are used to represent unknown values or variables.

This allows us to write general rules rather than specific results.

Example: “Twice a number” can be expressed as 2x.

2. Forming Expressions

Expressions are formed using numbers, letters, and mathematical operations such as addition, subtraction, multiplication, and division.

Example: “3 more than twice a number” is written as 2x + 3.

These expressions can be used to describe real-life problems like cost, area, age, and more.

3. Understanding Terms, Coefficients, and Operators

Terms: Parts of an expression separated by + or –.

Coefficient: The number multiplied with a variable.
Example: In 4x, 4 is the coefficient.

Operators: The symbols (+, –, ×, ÷) used in the expression.

4. Types of Expressions

Monomial: One term (e.g., 3x)

Binomial: Two terms (e.g., x + 4)

Polynomial: Multiple terms (e.g., 3x – 2y + 5)

5. Evaluating Expressions

Substituting specific values for variables to find the result of the expression.

Example: If x = 2, then 3x + 1 = 3(2) + 1 = 7.

6. Using Expressions in Real-Life Contexts

Students learn to write expressions for:

Age-related problems (e.g., “A person is x years old; 5 years later, they’ll be x + 5”)
Geometry (e.g., perimeter of square = 4x)
Money (e.g., cost of 5 pens at Rs. x each = 5x)

7. Expressing Rules in Arithmetic

This section encourages students to discover number patterns and represent them using algebraic expressions.

Example: nth odd number = 2n – 1

3.0Key Features of NCERT Solutions Class 7 Maths Chapter 4 : Expressions Using Letter-Numbers

Conceptual Clarity: Each solution is crafted to provide clear and concise explanations of concepts like variables, constants, terms, and coefficients, ensuring students grasp the core ideas of algebraic expressions.
Step-by-Step Solutions: All exercises from the NCERT Ganita Prakash textbook are solved with detailed, easy-to-follow steps. This methodical approach helps students understand the reasoning behind each solution and develop effective problem-solving strategies.
Real-World Relevance: The solutions link algebraic concepts to practical scenarios, such as age problems, perimeter calculations, and money calculations, demonstrating the applicability of expressions in everyday life.
Error Identification and Correction: Our solutions highlight common mistakes students make, especially during simplification and bracket removal, and provide correct explanations to prevent such errors in the future.