instruction: calculate the difference between boeing 's 2010 arms sales and raytheon 's 2010 arms sales .
response: SELECT ABS((SELECT "2010 arms sales (us$ m.)" FROM table_204_681 WHERE "company (country)" = 'boeing') - (SELECT "2010 arms sales (us$ m.)" FROM table_204_681 WHERE "company (country)" = 'raytheon'))