NCERT Solutions For Class 6 Maths Chapter 11 Exercise 11.4
Ncert Solutions for Class 6 Maths Chapter 11 Algebra Exercise 11.4:-
Exercise 11.4 Class 6 maths NCERT solutions Chapter 11 Algebra pdf download:-
Ncert Solution for Class 6 Maths Chapter 11 Algebra Exercise 11.4 Tips:-
Using Expressions Practically
We have already come across practical situations in which expressions are
useful. Let us remember some of them.
Situation (described in Variable Statements using
ordinary language) expressions
1. Sarita has 10 more Let Ameena Sarita has
marbles than Ameena. have x marbles. (x + 10) marbles.
2. Balu is 3 years Let Raju’s age Balu’s age is
younger than Raju. be x years. (x – 3) years.
3. Bikash is twice Let Raju’s age Bikash’s age
as old as Raju. be x years. is 2x years.
4. Raju’s father’s Let Raju’s age Raju’s father’s
age is 2 years more be x years. age is (3x + 2)
than 3 times Raju’s age. years.
Let us look at some other such situations.
Situation (described in Variable Statements using
ordinary language) expressions
5. How old will Susan Let y be Susan’s Five years from
be 5 years from now? present age in years. now Susan will
be (y + 5) years old.
6. How old was Susan Let y be Susan’s Four years ago,
4 years ago? present age in years. Susan was (y – 4) years old.
7. Price of wheat per kg Let price of rice Price of wheat
is Rs 5 less per kg be Rs p. per kg is Rs (p – 5).
than price of rice per kg.
8. Price of oil per litre Let price of rice Price of oil per
is 5 times the price of per kg be Rs p. litre is Rs 5p.
rice per kg.
9. The speed of a bus is Let the speed of the The speed of the
10 km/hour more than truck be y km/hour. bus is (y + 10) km/hour.
the speed of a truck
going on the same road.
Try to find more such situations. You will realise that there are many
statements in ordinary language, which you will be able to change to statements
using expressions with variables. In the next section, we shall see how we use
these statements using expressions for our purpose.
What have we discussed?
1. We looked at patterns of making letters and other shapes using matchsticks. We
learnt how to write the general relation between the number of matchsticks
required for repeating a given shape. The number of times a given shape is
repeated varies; it takes on values 1,2,3,… . It is a variable, denoted by some
letter like n.
2. A variable takes on different values, its value is not fixed. The length of a square can
have any value. It is a variable. But the number of angles of a triangle has a fixed value 3. It is not a variable.
3. We may use any letter n, l, m, p, x, y, z, etc. to
show a variable.
4. A variable allows us to express relations in any
practical situation.
5. Variables are numbers, although their value is not
fixed. We can do the operations of addition,
subtraction, multiplication and division on them
just as in the case of fixed numbers. Using
different operations we can form expressions
with variables like x – 3,
x + 3, 2n, 5m, 3p, 2y + 3, 3l – 5, etc.
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