Corner : A corner of a shape is a point in the shape such that this point does not lie on the line segment between any two other points in the shape. Every triangle has 3 corners and every quadrilateral has 4 corners.

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

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.

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

Cubic centimeter : A cubic centimeter or $cm^3$ is a unit to measure volume. A cubic centimeter is the volume of a cube with edge length 1 centimeter and we have $1,000,000 cm^3=1 m^3.$

Cubic meter : A cubic meter or $m^3$ is a unit to measure volume. A cubic meter is the volume of a cube with edge length 1 meter.

Hundred : Hundred refers to the number 100.

Million : A million refers to the number $1,000,000={10}^6.$

Fraction : A fraction is a number that can be written as $\frac{a}{b}$ with an integer $a$ and a natural numbers $b.$ A fraction $\frac{a}{b}$ is the result of the division $a\div b.$ Examples of fractions are $\frac{1}{2}, -\frac{2}{3}$ and $\frac{3}{2}.$

Integer : An integer is any ot the numbers $\ldots, -3, -2, -1, 0, 1, 2, 3, \ldots.$

Negative : A number is negative if it is $\lt 0.$

Positive : Positive means $\geq 0.$