Mixed Operations:
Within the hardware of a computer processor there is a component that does integer arithmetic and a separate component that does floating-point arithmetic.*  Arithmetic operations must go to one component or the other, and experience has shown that it is best to send mixed operations to the floating point unit.

(a) Mixed operations are sent to the floating point unit.  Ints are first converted to floats.
(b) Mathematically converting to float makes sense because every int can be trivially converted to a float.
    For example, 4 converts to 4.0


* Most modern processors have separate integer and floating-point hardware, but all floating-point operations can be done (slowly) in integer hardware.
