SQL Cast

cast(expr as name-of-type)
cast(multiset(subquery) as name-of-type)

create table c_ (
  a number(8,2),
  b number(8,6)
);

insert into c_ values(2.22,3.333333);

select * from c_;

create table c__ as 
  select cast(
            a as number(8,4)) c, 
            cast(b as number(8,4)) b
  from c_;

select * from c__;

desc c__;

drop table c_;