Terry Corporation had 300,000 shares of common stock outstanding at December 31, 2010. In addition, it had 90,000 stock options outstanding, which had been granted to certain executives, and which gave them the right to purchase shares of Terry's stock at an option price of $37 per share. The average market price of Terry's common stock for 2010 was $50.

REQUIRED: What is the number of shares that should be used in computing diluted earnings per share for the year ended December 31, 2010?