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

Number : A number $x$ is a mathematical symbol representing a quantity.

Addition : Addition is the mathematical operation that describes increasing a number by an amount equal to a second number. The mathematical symbol for addition is the plus sign $+.$ The term addition is also used for a generalization of this basic operation on numbers to functions, vectors and matrices.

Decimal point : The point in a decimal separating the digits representing multiples of wholes from the digits representing fractions of wholes.

Digit : A digit is a symbol used in the representation of a number.

Number : A number $x$ is a mathematical symbol representing a quantity.

Zero : The number 0.

Area : The amount of unit squares that is needed to cover a 2-dimensional shape.

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

Cube : A cube is a three-dimensional shape with 6 faces that are all squares. A cube has 8 corners and 12 edges.

Edge : An edge of a shape is a line segment between two corners of that shape.

Length : Length is the attribute of a one-dimensional shape that can be measured with a measuring tape.

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 $m^2.$

Surface area : The surface area of a three-dimensional shape is the area of the surface of the three-dimensional shape. For example the surface area of a cube with edge length 1 $cm$ is 6 $cm^2.$