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

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.

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.

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

Multiplication : Multiplication is the mathematical operation that is a shorthand for adding the same amount several times. For example $3\cdot 4=4+4+4=12.$

Standard algorithm : By standard algorithm we refer to any one of the algorithms that are commonly taught at school to add, subtract, multiply or divide multi-digit numbers such as long division and partial products multiplication.

Absolute value : The absolute value $|x|$ of a number $x$ is defined as the value of $x$ ignoring any potential minus sign. For example $|-2|=2$ and $|2|=2.$ In other words $|x|=x$ for $x\geq 0$ and $|x|=-x$ for $x\lt 0.$

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

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

Positive : Positive means $\geq 0.$

Subtraction : Subtraction is the mathematical operation that describes decreasing a number by an amount equal to a second number. The mathematical symbol for subtraction is the minus sign $-.$ The term subtraction is also used for a generalization of this basic operation on numbers to functions, vectors and matrices.

Sum : A sum is the result of an addition.