Math 105 Extra Credit

Extra Credit Assignment 1

Math Investigation 2.1 from the BBN websites looks at patterns of consecutive numbers.

Click the bold title to open the Math Investigation 2.1: Read Me - Consecutive Numbers.

Answer questions 1, 2 and 3 of the Starting Points for Investigations 2.1.

Carefully write up your detailed explanation of the three questions.

Up to 10 homework points extra credit.

Extra Credit is not accepted late; no exceptions. Check webpage for due date.

Extra Credit Assignment 2

PENNY TRICK

Why does the penny trick shown in class work?

Carefully write up your detailed explanation of why the trick works.

Up to 10 homework points extra credit.

Extra Credit is not accepted late; no exceptions.

Here is a review of what we did in class:

Penny Trick (Courtesy Dr. Edward Burger, Williams College)

• Start with some pennies
• Give a volunteer all of the pennies and ask the volunteer to secretly put 1 to 3 pennies in their pocket.
• Have the volunteer compute the sum of the digits of the number of pennies they have left (e.g. for 15, 1 + 5 = 6) and remove this many pennies from their hand and put them in their pocket with the others.
• Ask the volunteer to put some pennies on the table.
• How can I always tell how many pennies remain in the volunteer's hand?