How do we derive 2,400,000 and 2,640,000 in the first part of "a"?

E16-15 (Weighted-Average Number of Shares) Newton Inc. uses a calendar year for financial
reporting. The company is authorized to issue				9,000,000	shares of	$10
par common stock. At no time has Gogean issued any potentially dilutive securities. Listed below is a summary of Gogeans common stock activities.
							1. Number of common shares issued and outstanding at December 31, 2012						2,000,000
2. Shares issued as a result of a 10% stock dividend on September 30, 2013						200,000
3. Shares issued for cash on March 31, 2014						2,000,000
Number of common shares issued and outstanding at December 31, 2014						4,200,000
4. A 2-for-1 stock split of Gogeans common stock took place on March 31, 2015
Instructions:
(a) Compute the weighted average number of common shares used in computing earnings per common share for 2013 on the 2014 comparative income statement.
	Jan. 1, 2013Sept. 30, 2013 (2,400,000 9/12)					1,500,000
	Retroactive adjustment for stock dividend					110%
	Jan. 1, 2013Sept. 30, 201, as adjusted					1,650,000
	Oct. 1, 2013Dec. 31, 2013 (2,640,000 3/12)					550,000
Shares outstanding						2,200,000