note 2 2013 earnings per share the weighted average number of shares outstanding used to compute earnings per common share were as follows ( in millions ) : .
what was the ratio of the shares in 2012 to 2011 that were excluded in the calculation of the diluted earnings due to the anti-dilute nature
we compute basic and diluted earnings per common share by dividing net earnings by the respective weighted average number of common shares outstanding for the periods presented . our calculation of diluted earnings per common share includes the dilutive effects for the assumed exercise of stock options and vesting of restricted stock units based on the treasury stock method . the computation of diluted earnings per common share excluded 8.0 million , 13.4 million , and 14.7 million stock options for the years ended december 31 , 2012 , 2011 , and 2010 because their inclusion would have been anti-dilutive , primarily due to their exercise prices exceeding the average market price of our common stock during each respective reporting period . note 3 2013 information on business segments we organize our business segments based on the nature of the products and services offered . effective december 31 , 2012 , we operate in five business segments : aeronautics , information systems & global solutions ( is&gs ) , missiles and fire control ( mfc ) , mission systems and training ( mst ) , and space systems . this structure reflects the reorganization of our former electronic systems business segment into the new mfc and mst business segments in order to streamline our operations and enhance customer alignment . in connection with this reorganization , management layers at our former electronic systems business segment and our former global training and logistics ( gtl ) business were eliminated , and the former gtl business was split between the two new business segments . in addition , operating results for sandia corporation , which manages the sandia national laboratories for the u.s . department of energy , and our equity interest in the u.k . atomic weapons establishment joint venture were transferred from our former electronic systems business segment to our space systems business segment . the amounts , discussion , and presentation of our business segments reflect this reorganization for all years presented in this annual report on form 10-k . the following is a brief description of the activities of our business segments : 2030 aeronautics 2013 engaged in the research , design , development , manufacture , integration , sustainment , support , and upgrade of advanced military aircraft , including combat and air mobility aircraft , unmanned air vehicles , and related technologies . 2030 information systems & global solutions 2013 provides management services , integrated information technology solutions , and advanced technology systems and expertise across a broad spectrum of applications for civil , defense , intelligence , and other government customers . 2030 missiles and fire control 2013 provides air and missile defense systems ; tactical missiles and air-to-ground precision strike weapon systems ; fire control systems ; mission operations support , readiness , engineering support , and integration services ; logistics and other technical services ; and manned and unmanned ground vehicles . 2030 mission systems and training 2013 provides surface ship and submarine combat systems ; sea and land-based missile defense systems ; radar systems ; mission systems and sensors for rotary and fixed-wing aircraft ; littoral combat ships ; simulation and training services ; unmanned technologies and platforms ; ship systems integration ; and military and commercial training systems . 2030 space systems 2013 engaged in the research and development , design , engineering , and production of satellites , strategic and defensive missile systems , and space transportation systems . space systems is also responsible for various classified systems and services in support of vital national security systems . operating results for our space systems business segment include our equity interests in united launch alliance , which provides expendable launch services for the u.s . government , united space alliance , which provided processing activities for the space shuttle program and is winding down following the completion of the last space shuttle mission in 2011 , and a joint venture that manages the u.k . 2019s atomic weapons establishment program. .