2 + 4/2 + 1
    ---
2 +  2  + 1
------
  4     + 1
  ---------
       5

Unary Minus

If you look in the table of operators you will see that the character - is listed twice. That is because - is used for two purposes. In some contexts, - is the unary minus operator. In other contexts, - is the subtraction operator.

The unary minus is used to show a negative number. For example:

-97.34

means "negative ninety seven point thirty four." The subtraction operator is used to show a subtraction of one number from another. For example:

95 - 12

is an expression that calls for 12 to be subtracted from 95. The unary minus operator has high precedence. Addition and subtraction have low precedence. For example

-12 + 3

means add 3 to negative 12 (resulting in -9). The unary plus + can be applied to a number to show that it is positive. It also has high precidence. It is rarely used.

+24 + 3 * -4