flotingpoint value insertion error

i had create the following table in oracle 10g express edition.

CREATE TABLE employee

(

employeeid VARCHAR(9) NOT NULL,

fname varchar(8),

minit VARCHAR(2),

lname VARCHAR(8),

bdate DATE,

address VARCHAR(27),

sex VARCHAR(1),

salary NUMBER(7,5) NOT NULL,

superempid VARCHAR(9),

dno NUMBER(1) NOT NULL

) ;

and i am inserting the value in the table in the following way:

insert into employee values('emp_1','kalpana','ka','jaiswal','29-May-1996','bhy','f',25000.500,1,100);

But it is giving me following error how to solve that error?

ORA-01438: value larger than specified precision allowed for this column