- Variable
A variable denotes a quantity (or letter or symbol) which is able to represent different
numerical values. In other words, a variable denotes a quantity whose value changes
depending upon the situations.
Generally, x, y, z are the three variables which are used most frequently. Depending
upon the need, certain other alphabets are also treated as variables.
Note : 1. All the numerals are constants.
- To denote variables, the English alphabets from A to Z (or) a to z, excepting
o, i, j, k are used.
The concept can be taught to the child orally, and then focusing on the difference
between a constant and a variable.
- Power (or Exponent or Index) of a variable
The power of a literal indicates the number of times the base (variable) has been
multiplied by itself.
Eg. : a × a × a × a = a^4
In the above example the variable ‘a’ occurs four times and hence it can be denoted as
a^4 , which is to be read as ‘a’ to the power of ‘4’. Note that in a^4 , a is called as the base
and 4 is called the power. The term power is also called as exponent or index.
The idea may be explained to the child orally, focusing on the point that the amount
of times a particular number is repeated becomes the power.
- Coefficient
The numeral (or constant) which precedes the variable or the product of variables is
called as the coefficient.
Eg. : Consider 2x. Here the constant is 2 and the variable is x. Therefore the constant
2 is called as the coefficient.
The idea may be explained to the child orally.
