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.

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.

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

Product : A product is the result of a multiplication.

Rectangle : A rectangle is a quadrilateral with 4 right angles. Two opposing sides in a rectangle have the same length. They are sometimes referred to as the width and the length of the rectangle. To calculate the area of an rectangle one can multiply the width of the rectangle by the length of the rectangle. A square is the special case of a rectangle in which all side lengths are the same. Every rectangle is a parallelogram.

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 $m^2.$

Cube root : The cube root of $x$, normally written as $\sqrt[3]{x}$ or as $x^{\frac{1}{3}}$ is the number whose third power equals $x$. In other words it is defined as the solution of the equation $(\sqrt[3]{x})^3=x.$

Fractional exponent : The definition of a power with a fractional exponent is $x^\frac{a}{b}:=\sqrt[b]{{x}^a}.$ For example $8^{\frac{2}{3}}=\sqrt[3]{{8}^2}=4.$

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

Power : A power is a number of the form $a^b.$ $b$ is called the exponent of the power and $a^b$ is called a power of $a$. For natural numbers $b$ the number $a^b$ is an abbreviation for successively multiplying $a$ by itself $b$ times. For example $2^3=2\cdot 2\cdot 2=8.$ For fractional exponents $b=\frac{p}{q}$ the number $a^{\frac{p}{q}}$ is defined as $\sqrt[q]{a^p}.$ For arbitrary real exponents $b$ the power $a^b$ is defined as the limit of $a^{b_n}$ with rational $b_n$ that converge towards $b.$

Third : A third either refers to the third object in an ordering or to the number $\frac{1}{3}=0.\overline{3}.$