Algebra For Class 6

Algebra For Class 6

Team Careers360Updated on 02 Jul 2025, 05:27 PM IST

If we wish to define what is algebra, we can say it as a branch of mathematics in which we use letters to denote numbers. Now these letters are nothing but the english alphabets that we have studied and known so far. In algebra, we assume the value of some unknown numerical constant to be a variable in an equation and then we solve the equation till we find the unknown quantity.

This Story also Contains

  1. What is Algebra?
  2. Algebra Class 6 Notes
  3. Algebra Class 6 Questions and Answers
Algebra For Class 6
Algebra

This article is about the concept of algebra class 6 ncert. In this article, we will learn about introduction to algebra class 6, the basics of algebra, algebra class 6 solutions, etc.

What is Algebra?

Algebra is a branch of mathematics that deals with variables and constants. An algebraic expression is a combination of variables and constant. Algebra includes almost everything ranging from solving elementary equations to the study of abstractions. It is really helpful in finding the unknown quantities assuming them as variables and solving the equations.

We use letters called variables, to represent the unknown quantities in maths. The use of letters helps us in various ways as listed below:

  • It makes the process of writing rules and formulas in very simple way.
  • We do not have to talk about just one number but we can talk of many numbers at the same time.
  • The variables help us to represent unknown quantities and solve daily life problems within no time.
  • They also enable us to perform mathematical operations like addition, subtraction, multiplication, and division on numbers in form of variables.

Algebra Class 6 Notes

Algebra class 6 notes include the concepts of variables and constants, algebraic equations and how to solve such equations.

Variable and Constants

A variable is a quantity that may change. Hence, its value is not fixed and may take different values. Variables are expressed as small letters like a,b,c,x,y,z,....

A constant is a quantity that does not change.

For example, you and your friend go to buy pencils. The cost of one pencil is Rs. 5. The amount to be paid is $5x$ where $x$ is the number of pencils. You buy 5 pencils and your friend buys 4 pencils. Here, the value of $x$ is 5 and 4. From this, we could say that the value of $x$ is not fixed, it keeps on changing. So, $x$ is a variable.

But the price of the pencil is not going to change. So, the cost of one pencil that is Rs.5 is a constant.

Similarly, consider the area of square formula, $A = x^2$. Here, the length of the side$(x)$ is not fixed. So, $x$ is a variable. But the number sides in a square is always four. So, 4 is a constant.

Algebraic Equations

Algebraic equations are combinations of variables and constant. Eg. $2x=38$, $3x+7y=22$, etc.

Algebraic equations with one variable

Let us consider the previous example. You go to buy pencils. The cost of one pencil is Rs. 5. You pay Rs.35 to the shopkeeper. Let $x$ be the number of pencils.

Now, let us form a algebraic equation for this situation. The algebraic equation is $5x = 35$ where $x$ is the number of pencils.

By solving this equation, we can find the number of pencils you bought.

Now, let us look into another example to understand the algebraic equation with two variables.

Algebraic equations with two variables

Raju and Balu are brothers. When Raju is 12 years old, Balu is 9 years old. When Raju is 15 years old, Balu is 12 years old. From this, we could say that Raju is 3 years older than Balu.

Now let $y$ be Raju's age and $x$ be Balu's age. This can be expressed as a algebraic equation as $y = x+3$. If we know Balu's age, then, we can put the value in $x$ and find Raju's age. Suppose Balu is 20 years old, then Raju's age is, $y=20+3 = 23$.

Similarly, if we know Raju's age, then, we can put the value in $y$ and find Balu's age. Suppose Raju is 17 years old, then Balu's age is, $17 = x+3$. This can be written as $x=17-3 = 14$. So, Balu is 14 years old when Raju is 17 years old.

How do we solve an algebraic equation?

We solve equations until the left hand side equation is equal to right hand side equaiton. For example, equation 2x = 4 is satisfied for the value of x = 2 only. As we can write $x = \frac{4}{2} = 2$.

Now, let us look into some algebra class 6 extra questions.

Algebra Class 6 Questions and Answers

Example 1: Cadets are marching in a Republic Day parade. There are 10 cadets in a row. Find out the rule which gives the number of cadets.

Solution: Let us suppose that $p$ be the number of rows
Given that number of cadets present in a row $=10$
Hence total number of cadets $=$ number of cadets in a row $\times$ total number of rows $
=10 p
$


Example 2: If there are $\mathbf{2 0}$ pencils in a box, how will you write the total number of pencils in terms of the number of boxes?

Solution: Let us suppose that $x$ be the number of boxes
Given that number of pencils in a box $=20$
Hence total number of pencils $=$ number of pencils in a box $\times$ total number of boxes $=20 x$

Example 3: The professor in a college distributes 2 fountain pens per student. Can you tell how many pens are needed in all ?

Solution: Let us take $r$ be the total number of students
From question, pens given to each student $=2$
Therefore total number of pens $=$ number of pens given to each student $\times$ total number of students $=2 \mathrm{r}$

Example 4: An eagle flies 3 km in one minute. Express the distance covered by the eagle in terms of its flying time in minutes.

Solution: Let z minutes be the flying time
We are given that distance covered in one minute $=3 \mathrm{~km}$
Hence, distance covered in z minutes $=$ Distance covered in one minute $\times$ total flying time $=1 \times z=z \mathrm{~km}$

Example 5: The side of a square is denoted by p. Express the perimeter of the square using
p.

Solution: Side of square $=p$
Perimeter of square $=p+p+p+p=4 p$

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Frequently Asked Questions (FAQs)

Q: How do you use cross multiplication to solve proportions?
A:
Cross multiplication is a method for solving proportions by multiplying the numerator of each fraction by the denominator of the other fraction. This technique simplifies the process of solving proportions and is widely used in various applications.
Q: What is the difference between ratio and proportion?
A:
A ratio is a comparison of two quantities, while a proportion is an equation stating that two ratios are equal. Understanding the relationship between ratios and proportions is crucial for solving problems involving scaling, mixtures, and comparisons.
Q: How do you solve word problems involving rates, time, and distance?
A:
To solve rate-time-distance problems, use the formula Distance = Rate × Time. Identify the given information and the unknown, then set up an equation to solve. This approach helps in tackling many real-world problems involving motion and speed.
Q: What is the concept of absolute value, and how does it relate to distance?
A:
The absolute value of a number is its distance from zero on a number line, regardless of direction. It's always non-negative and relates to the concept of magnitude or distance. Understanding absolute value is crucial for solving certain types of equations and inequalities.
Q: How do you represent and interpret inequalities on a number line?
A:
Inequalities are represented on a number line using open or closed circles for the endpoint and a line or arrow to show the included values. This visual representation helps in understanding the range of values that satisfy the inequality.
Q: How can you determine if a number is divisible by 2, 3, or 5 without actually dividing?
A:
For 2: If the last digit is even (0, 2, 4, 6, or 8).
Q: What is the difference between discrete and continuous data?
A:
Discrete data can only take specific values (like whole numbers), while continuous data can take any value within a range. Understanding this difference is important for choosing appropriate mathematical models and representations.
Q: How do you interpret the slope and y-intercept of a linear equation?
A:
In the equation y = mx + b, m represents the slope (rate of change) and b represents the y-intercept (where the line crosses the y-axis). Interpreting these values helps in understanding the behavior and position of the line.
Q: What are linear equations, and how do they relate to straight lines?
A:
Linear equations are equations where the variable has a degree of 1 (e.g., y = mx + b). They represent straight lines when graphed on a coordinate plane. Understanding linear equations is fundamental to graphing and solving many real-world problems.
Q: How do you factor algebraic expressions, and why is it useful?
A:
Factoring involves finding the factors of an algebraic expression. Common techniques include finding common factors, grouping, and recognizing special patterns. Factoring is useful for simplifying expressions, solving equations, and understanding the structure of polynomials.