CREATE TABLE table_203_737 (id DECIMAL, "#" DECIMAL, "employer" TEXT, "# of employees" DECIMAL)

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