## Ncert Solutions for Class 6 Maths Chapter 11 Algebra Exercise 11.1:-

**Exercise 11.1**Ā Class 6 maths NCERT solutions Chapter 11 Algebra pdf download:-

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### Ncert Solution for Class 6 Maths Chapter 11 Algebra Exercise 11.1 Tips:-

**Introduction:-**

Our study so far has been with numbers and shapes. We have learnt numbers,

operations on numbers and properties of numbers. We applied our knowledge

of numbers to various problems in our life. The branch of mathematics in

which we studied numbers is arithmetic. We have also learnt about figures in

two and three dimensions and their properties. The branch of mathematics in

which we studied shapes is geometry. Now we begin the study of another

branch of mathematics. It is called algebra.

The main feature of the new branch which we are going to study is the use

of letters. Use of letters will allow us to write rules and formulas in a general

way. By using letters, we can talk about any number and not just a particular

number. Secondly, letters may stand for unknown quantities. By learning

methods of determining unknowns, we develop powerful tools for solving

puzzles and many problems from daily life. Thirdly, since letters stand for

numbers, operations can be performed on them as on numbers. This leads to

the study of algebraic expressions and their properties.

You will find algebra interesting and useful. It is very useful in solving

problems. Let us begin our study with simple examples.

**The Idea of a Variable:-**

In the above example, we found a rule to give the number of matchsticks

required to make a pattern of Ls. The rule was :

Number of matchsticks required = 2n

Here, n is the number of Ls in the pattern, and n takes values 1, 2, 3, 4,…. Let

us look at Table 1 once again. In the table, the value of n goes on changing

(increasing). As a result, the number of matchsticks required also goes on

changing (increasing).

n is an example of a variable. Its value is not fixed; it can take any value

1, 2, 3, 4, … . We wrote the rule for the number of matchsticks required

using the variable n.

The word āvariableā means something that can vary, i.e. change. The value

of a variable is not fixed. It can take different values.

We shall look at another example of matchstick patterns to learn more

about variables.

**More Examples of Variables:-**

We have used the letter n to show a variable. Raju asks, āWhy not mā?

There is nothing special about n, any letter can be used.

One may use any letter as m, l, p, x, y, z etc. to show

a variable. Remember, a variable is a number which

does not have a fixed value. For example, the number

5 or the number 100 or any other given number is

not a variable. They have fixed values. Similarly, the

number of angles of a triangle has a fixed value i.e. 3.

It is not a variable. The number of corners of a

quadrilateral (4) is fixed; it is also not a variable.

But n in the examples we have looked is a variable.

It takes on various values 1, 2, 3, 4, … .