EXPRESSIONS We have studied the following in the previous term. 11 = (1 x 10) + 1, 12 = (1 x 10) + 2 20 = (2 x 10) + 0 ... In the above numerical expressions we have used only numbers 1, 2, 3 ... To form numerical expressions we use addition, subtraction, multiplication and division signs.

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

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

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

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