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since they hold the places. ‘x’ is one such a place holder used to denote an unknown

value.

3. Literals
   In the expression of a mathematical statement, place holders are used to represent
   unknown numbers. Letters like a, b, c, x, y, etc., are also used to represent
   unknown numbers in place of the place holders. These letters, which are used to
   represent numbers are called as literals.

Eg. : Consider the statement, “the product of 4 and another number becomes 20”.

Using literals, the statement can be rewritten as, 4 ×^ b = 20. Here, ‘b’ is a literal used

to denote an unknown value.

Note : The word literal is derived from “litera” a Latin word meaning “a letter of the

alphabet”.

The idea may be explained to the child orally supported by relevant text material in

Braille.

4. Constants
   A quantity that takes a fixed numerical value is called a constant. The term ‘constant’
   literally means a number or quantity that does not change its value. In Algebra too,
   the term means the same. Numerals are always constants, and in addition, certain
   other alphabets such as a, b, etc., can also be treated as constants depending upon
   the situations.

Eg. : 1,4,7, 15 etc., are all constants.

The idea of constant can be taught to the child orally, explaining its literal meaning

and its usage in mathematics.