Exhibit 11.1 DATA SYSTEMS & SOFTWARE INC. AND SUBSIDIARIES Calculation of Primary Earnings Per Common Share Six months ended Three months ended June 30, June 30, --------------------- ---------------------- 1996 1997 1996 1997 --------- --------- --------- ---------- Net income $1,063,810 $4,382,106 $ 308,981 $( 986,084) ========= ========= ========= ========= Weighted average number of: Common shares outstanding 7,310,514 7,369,178 7,361,402 7,369,178 Dilutive common equivalents 114,814 2,427 172,626 2,702 --------- --------- --------- --------- Total 7,425,328 7,371,605 7,534,028 7,371,880 ========= ========= ========= ========= Earnings per share $ 0.14 $ (0.59) $ 0.04 $ (0.13) ========= ========= ========= ========= Earnings per share assuming full dilution are identical to primary earnings per share.