**TREE DIAGRAM - **It is a diagram that shows all the possible results of an event (widely used in programming).

**DIAMETER** - In the circle, it is the line segment that passes through the center and joins two points of the circle's circumference.

**DIFFERENCE - **The result of a subtraction.

**DIGITS** - Symbols used to write numbers in decimal representation or some other base. In decimal notation the digits used are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. In binary notation only two digits 0 and 1 are used.

**DIMENSION** - For example: A line has one dimension, a rectangle has two dimensions, a cube has three dimensions.

**DISTANCE BETWEEN TWO POINTS** - The magnitude of the line segment joining two points. Example: Let the points be P_{1}(x_{1}, y_{1}) and P_{2}(x_{2} and y_{2}), we calculate the distance between these two points using the following formula _{}.

**DISTRIBUTING - **Law that allows to distribute an addition or subtraction in relation to the product, without changing the result.

A × (B + C) = (A × B) + (A × C)

A × (B - C) = (A × B) - (A × C)

**DIVIDING - **The number that will be divided into a division operation. In operation 9 ÷ 3 = 3, 9 is the dividend.

**DIVISION - **One of the four basic operations of arithmetic. Used to know the number of times a number is contained in another number.

**DIVISIBILITY **- Obtaining rest in the entire division.

**DIVIDER **- It's the second term of the division. It is what divides the dividend. In operation 15 ÷ 5 = 3, 5 is the divisor.

**PRIME DIVIDERS** - It is said of the dividers of a number that are prime numbers such as: 2, 3, 5, 7, 11, 13, 17, 19, 23, 31…

**PERIODIC TENTH** - Decimal part of a number that repeats indefinitely. Example: 2,345345345…

**DOUBLE - **Twice bigger.

**DODECAGON - **A 12-sided polygon.

**DOMAIN OF A FUNCTION** - The set of values taken by the independent variable. It is represented by *Sun*.

**DOZEN** - Group of 12 units.

A - B - C - D - E - F - G - H - I / J / K - L - M - N - O - P - Q - R - S - T - U / V - X / Z