Count : To count means to find out the number of objects by adding one for every object.

Centimeter : A centimeter ($cm$) is $\frac{1}{100}$ of a meter.

Hundred : Hundred refers to the number 100.

Square centimeter : Square centimeter or $cm^2$ is a unit of measurement for measuring area. 1 square centimeter is the area of a square with side length 1 $cm,$ so 10,000 $cm^2$ are one $m^2.$

Square meter : Square meter or $m^2$ is a unit of measurement for measuring area. 1 square meter is the area of a square with side length 1 $m.$

Ten thousand : Ten thousand refers to the number $10,000=10^4.$

Expression : An expression is a succession of constants, variables and mathematical operations that if evaluated for specific values of the variables represents a number.

Variable : A letter in an expression or function that represents an arbitrary number.