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

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

Ones digit : The first digit left of the decimal point (or the digit furthest to the right if there is no decimal point). It counts multiples of 1.

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

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

Cone : A cone is a three-dimensional shape that has a base circle and a point called the vertex such that all lines from the vertex to the circumference of the circle are part of the shape.

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 $1,000,000 cm^3=1 m^3.$

Cylinder : A cylinder is a three-dimensional shape that looks like a can. It has two faces that are circles and a wrapped around rectangle face that sits perpendicular in between these two circles.

Equation : An equation is a mathematical statement in which two expressions are written with an equal sign in between. A solution of an equation is a set of variables that makes the statement a true statement.

Height : In a triangle a height (or altitude) is the shortest line segment that connects a side to its opposing corner. A height of a triangle is perpendicular to the side is started at. The three heights of a triangle intersect in a point, the so called orthocenter of the triangle. In a parallelogram the height is the shortest distance between two opposing sides. In a pyramid the height is the shortest distance between the base area and the corner of the pyramid that is not part of the base area. In a prism the height is the shortest distance between the two base faces.

Pi : Pi or $\pi$ is an irrational number approximately equal to 3.14 that is defined as the quotient of the circumference and the diameter of a circle.

Radius : In a circle or sphere the radius is the distance between the center and the boundary.

Volume : Volume refers to the size of a three-dimensional objects measured by how many unit cubes it would take to fill the shape.