Exhibit No. 11 CNS, INC. Computation of Net Income per Share of Common Stock (unaudited) Three Months Ended Six Months Ended June 30, June 30, ------------------------- ------------------------- 1998 1997 1998 1997 ----------- ----------- ----------- ----------- NET INCOME Net income $ 815,888 $ 2,613,473 $ 831,174 $ 3,934,966 =========== =========== =========== =========== BASIC EARNINGS PER SHARE: Weighted average number of common shares outstanding 18,445,000 19,277,000 18,419,000 19,241,000 =========== =========== =========== =========== Basic earnings per share $ .04 $ .14 $ .05 $ .20 =========== =========== =========== =========== DILUTED EARNINGS PER SHARE Weighted average number of common shares outstanding 18,445,000 19,277,000 18,419,000 19,241,000 Incentive stock options 66,000 436,000 81,000 485,000 Nonqualified stock options 97,000 266,000 132,000 296,000 ----------- ----------- ----------- ----------- 18,608,000 19,979,000 18,632,000 20,022,000 =========== =========== =========== =========== Diluted earnings per share $ .04 $ .13 $ .04 $ .20 =========== =========== =========== =========== 12