Here is the answer.
Numeric promotions are used to convert the operands in a numeric expression to a common type before an operation is performed between the operands.
Numeric promotion is a property of the specific definitions of the built-in operations and not a Java language feature. It is applied to the operands of an arithmetic operator. Numeric promotion is the conversion of a smaller numeric type to a larger numeric type,so that integer and floating-point operations may take place.