sign
This is the term used for a symbol which is used to show an operation.
Here are some of the most common signs:
A plus sign and a minus sign are used to show whether a number is positive or negative.
For example, +12, –3.
These signs show in which direction the number is located from the origin. The number line shows this.
However, positive numbers do not always show the plus sign, therefore, ‘3’ is really ‘+3’.