What Have We Discussed ?

We have 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 variableconstant, denoted by some letter.

A variable takes on different values, its value is not fixed.

For example: The length of a square is variablefixednone of the options while the number of sides of a square is fixednone of the optionsvariable.

A variable allows us to express relations in any practical situation.

Variables are numbersconstants, even if 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, just as in the case of fixed numbers.

Using different operations we can form expressions with variables like x−3, x+3, 2n, 5m, p3 , 2y+3, 3l−5, etc.