Operand

The operand '3' is one of the inputs (quantities) followed by the addition operator, and the operand '6' is the other input necessary for the operation.

The result of the operation is 9. (The number '9' is also called the sum of the addends, 3 and 6.)

An operand, then, is also referred to as "one of the inputs (quantities) for an operation".

Read more about Operand:  Computer Science