create table test_func(id number,num varchar2(20));

insert into test_func values(1,'34.5678');

select * from test_func where id =1;

select round(num,2) from test_func where id =1;

select round(num/2,2) from test_func where id =1;

select trunc(num,2) from test_func where id =1;

insert into test_func values(2,'55');

select num from test_func where id =2;

select mod(num,2) from test_func where id =2;