Monroe incorrectly calculates that the overdue books would cost Henry over a $1000. However at 0.10¢ a day for 5 years and 23 days it would only be roughly $185 (365 days x 5 years= 1825 + 23 days = 1848 days x .10 cents = $184.80) if Henry had just done the math himself, he would not have worked himself into such a frenzy.