Even the best speech recognizer have only 99% accuracy per digit. While this might seem high, the user only has a 90% of getting all ten digits in a row correct. Because of this, any sequence of digits that are entered should be played back to the user for verification. If the speech engine misrecognized any of them the application should break the digits into groupings and have the user speak and verify each of the groups. Because the groups have fewer digits they have a higher accuracy. Almost all long sequences of digits are grouped by convention. Example: Phone numbers in the United States of America are two groups of three digits each followed by a group of four digits.