SQL> select 5302239.56 + round(22927.000000 * 234.500000, 2) from rdb$database
CON> ;

                  ADD
=====================
Statement failed, SQLSTATE = 22003
Integer overflow.  The result of an integer operation caused the most significant bit of the result to carry.
SQL>

select 5302239.56 + round(1e0 * 22927.000000 * 234.500000, 2) from rdb$database

select 22927.000000 * 234.500000 from rdb$database