ORBIT GAR ANT DRILLING INC. NOTES TO THE CONSOLID A TED FINANCIAL ST A TEMENTS (Continued) (Amounts as at March 31, 2008 and for the nine and three months ended March 31, 2008 and for the six and three months ended March 31, 2007 are unaudited) 11. SHARE C APIT AL (Continued) The company’s calculations of the fair value of the 1,017,000 options granted during the 9 months ended June 30, 2007 were made using the Black-Scholes option-pricing model with weighted average assumptions as follows: Risk-free interest rate ................................................................ 4.10% Expected life ..................................................................... 5 years Expected volatility .................................................................. 4 6 % Expected dividend yield .............................................................. 0 % F air value of options granted ........................................................... $0.46 The company’s calculations of the fair value of the 38,500 options granted during the 9 months ended March 31, 2008 were made u sing the Black-Scholes option-pricing model with weighted average assumptions as follows: Risk-free interest rate ................................................................ 4.10% Expected life ..................................................................... 5 years Expected volatility .................................................................. 4 4 % Expected dividend yield .............................................................. 0 % F air value of options granted ........................................................... $0.66 Earnings per share Diluted earnings per common share were calculated based on net earnings divided by the average number of common shares outstanding taking into account the dilution effect of stock options using the treasury stock method. March 31, March 31, March 31, March 31, June 30, 2008 2007 2008 2007 2007 (3 months) (3 months) (9 months) (6 months) (9 months) (unaudited) (unaudited) (unaudited) (unaudited) $$$$$ Earnings per share — basic Net earnings available to common shareholders ...... 2,823,920 637,313 7,960,492 659,999 1,899,093 A verage basic number of common shares outstanding . . 24,776,536 18,982,584 24,771,591 14,392,582 17,760,450 Earnings per share — basic ................... 0.11 0.03 0.32 0.05 0.11 Earnings per share — diluted Net earnings available to common shareholders ...... 2,823,920 637,313 7,960,492 659,999 1,899,093 A verage basic number of common shares outstanding . . 24,776,536 18,982,584 24,771,591 14,392,582 17,760,450 A djustment to average number of common shares Stock options .......................... 716,550 942,000 859,800 942,000 813,600 A verage diluted number of common shares outstanding . 25,493,086 19,924,584 25,631,391 15,334,582 18,574,050 Earnings per share — diluted ................. 0.11 0.03 0.31 0.04 0.10 F-21