create or replace
FUNCTION centfer(i IN NUMBER)
RETURN NUMBER AS
v_num NUMBER;j NUMBER;
BEGIN
v_num :=((i * 9/5) + 32 );
j:= v_num;
RETURN j ;
END centfer;

Now execute this query, as shown below:

show user;
Select ename, empno, centfer(35) from emp
where ename='MILLER';