EXHIBIT NO. 11(a) ARMSTRONG HOLDINGS, INC. AND SUBSIDIARIES COMPUTATION FOR BASIC EARNINGS PER SHARE FOR THE YEARS ENDED DECEMBER 31 (AMOUNTS IN MILLIONS EXCEPT FOR PER-SHARE DATA) 2001 2000 1999 ------ ------ ------ Basic earnings per share - ------------------------ Net earnings $ 92.8 $ 12.2 $ 14.3 Average number of common shares outstanding 40.5 40.2 39.9 Basic earnings per share $ 2.29 $ 0.30 $ 0.36