The amounts used in computing earnings per common share and the effects of potentially dilutive securities on the weighted average number of common shares were as follows:

	Three Months Ended
	March 31,
	2018		2017
(Dollars and shares in millions, except per share amounts)
Net income attributable to U.S. Cellular shareholders	$	45	$	26

Weighted average number of shares used in basic earnings per share		85		85
Effects of dilutive securities		1		1
Weighted average number of shares used in diluted earnings per share		86		86

Basic earnings per share attributable to U.S. Cellular shareholders	$	0.52	$	0.31

Diluted earnings per share attributable to U.S. Cellular shareholders	$	0.52	$	0.31