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_204_582 ( id number, "model" text, "launch" text, "code name" text, "fab (nm)" number, "bus interface" text, "memory (mib)" text, "core clock (mhz)" number, "memory clock (mhz)" number, "config core1" text, "fillrate\nmoperations/s" number, "fillrate\nmpixels/s" number, "fillrate\nmtextels/s" number, "fillrate\nmvertices/s" number, "memory\nbandwidth (gb/s)" number, "memory\nbus type" text, "memory\nbus width (bit)" number, "directx support" number )

### Question ###
tell me the number with a fab of 500 nm .

### Accurate SQL ###

SELECT COUNT(*) FROM table_204_582 WHERE "fab (nm)" = 500