Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_1876825_7 ( no_in_series VARCHAR, production_code VARCHAR )

### Question ###
Name the number of number in series for production code of 06-04-621

### Accurate SQL ###

SELECT COUNT(no_in_series) FROM table_1876825_7 WHERE production_code = "06-04-621"