CREATE TABLE table_69433 ("School" TEXT, "Location" TEXT, "Mascot" TEXT, "# / County" TEXT, "IHSAA Class" TEXT, "Year Joined" FLOAT, "Previous Conference" TEXT)

which # / county is correct for year less than 1981 and chalmers as location?
SELECT "# / County" FROM table_69433 WHERE "Year Joined" < '1981' AND "Location" = 'chalmers'
SELECT "# / County" FROM "table_69433" WHERE "Location" = 'chalmers' AND "Year Joined" < '1981'