1. EXPRESSIONS
We have studied the following in the previous term. 11 = (1 x 10) + 1, 12 = (1 x 10) = (2 x 10) In the above numerical expressions we have used only numbers 1, 2, To form numerical expressions we use addition, subtraction, multiplication and division signs.

2. VARIABLES
A variable can take any numerical value and is represented by alphabets.
All operations +, –, x and ÷ are used for numbers, which are also applicable for variable.
Example:- l , m, n , 3x , 4z

3. Constants
A constant can take numerical value. It’s value does not change.
Example:- 2 , 2.5 ,

4. Expressions Variables Constants x+5 x 5 y-7 y 7 8z z 8 m÷6 m 6 r 0.7+m
Expressions
Variables
Constants
x+5 x 5
y-7 y 7 8z z 8
m÷6 m 6 r
0.7+m
0.7
3h-5 h
3, 5

5. TRY THIS
List out the variables and constants: x, 4, yz, 3m, 5.4 , 6b,17, 25,6h,