unary operator (operator taking one operand)

(mathematics, computing) A function or other mapping that carries variables defined on a domain into another variable; operator.

one thing

operate (machinery)

maneuver, operate

a child / (figuratively) a girl, especially a dear or desired one (compare use of English baby, babe) / a smaller or younger version of a bigger object

(arithmetic) arithmetic operator

(mathematics, computing) operand

to calculate

(mathematics) A procedure for generating a value from one or more other values; operation.