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_203_737 ( id number, "#" number, "employer" text, "# of employees" number )

### Question ###
what is the difference between the number of employees at mundelein elementary school district 75 and fremon school district 79 ?

### Accurate SQL ###

SELECT ABS((SELECT "# of employees" FROM table_203_737 WHERE "employer" = 'mundelein elementary school district 75') - (SELECT "# of employees" FROM table_203_737 WHERE "employer" = 'fremont school district 79'))