NCERT Solutions For Class 6 Maths Chapter 11 Exercise 11.1
Ncert Solutions for Class 6 Maths Chapter 11 Algebra Exercise 11.1:-
Exercise 11.1 Class 6 maths NCERT solutions Chapter 11 Algebra pdf download:-
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 ‘variable’ 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, “Why not m”?
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, … .
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