Error insert

i have problem while insert data in the table.
i have function to copy data between 2 table, like table A to table B. but when i am run this function, data table B not match with table A.
example, i have record in table A with value 1.73 but value will change in table B to 2.00, why? i have used round function to get this record but is not work.

If you are using round function, then it make sense. round function will round 1.75 to 2
postgres=# select round(1.75)
postgres-# ;
round
-------
2
(1 row)

If issue is something else, then please share sample test case. So, that I can look into it.