Wall Street analysts have predicted Apple iPad sales will be in a range between 2 million to as high as 10 million in the first year. Angela McIntyre of Gartner puts the number at 4.2 million. The uncertainty around the iPad sales pace helped knock Apple's stock down 1% Monday. The shares were down and additional 42 cents, or less than 1%, to $223.42 in morning trading Tuesday. --Written by Scott Moritz in New York.