Negative vs Subtraction The negative key  (-)  at the bottom of the keyboard is for entering negative numbers. For example: - 2  x  - 3 =   6 The subtract key is used for subtracting. For example: 17   -  7 =   10 Sometimes you have to use them both in one calculation. For example: -  2 -  -  3    =   1 You can tell them apart on the screen ... the negative sign is smaller and higher. In general, a negative sign is used in front of a negative number, while a subtract sign is used to subtract. Although you can use either interchangeably when doing a calculation on paper, if you mix them up on a TI83, the calculator won't give you the correct answer. MENU