Answer all the questions below and press submit to see how many you got right.
Expression : An expression is a succession of constants, variables and mathematical operations that if evaluated for specific values of the variables represents a number.
What is the value of the expression $x^2$ for $x=12?$
What is the value of the expression $(x+1)(x-1)$ for $x=4?$
Number : A number $x$ is a mathematical symbol representing a quantity.
What is the value of the expression $x$ for $x=-6?$