CREATE TABLE table_204_828 (id DECIMAL, "whitworth size  ( in ) " DECIMAL, "core diameter  ( in ) " DECIMAL, "threads per inch" DECIMAL, "pitch  ( in ) " DECIMAL, "tapping drill size" TEXT)

what is the total of the first two core diameters ?
SELECT SUM("core diameter (in)") FROM table_204_828 WHERE id <= 2
SELECT SUM("core diameter (in)") FROM "table_204_828" WHERE "id" <= 2