The Famous Jinx Puzzle
Student's page 2
Revised 6.7.10

The Jinx Calculator
To help you find out if this puzzle will work for all numbers, we will use a special spreadsheet “calculator." Here's what your Jinx Calculator will look when you open it. Notice that 6 was the chosen number and entered in cell B1.

The spreadsheet then quickly did all the calculations and the answer was once again 13 - the unlucky number. Can you find a number that will make the puzzle not end in 13 (and not jinx you?) Use the Excel version of the Jinx Calculator to help you.

(Hint: Try different kinds of numbers not just whole numbers.  Like these: 2.5, -56, 3000, 999999999, .000005. Fractions can also be tried. For example if you try 1/2, you enter =1/2 into the cell.

Share a few of your interesting examples of numbers that you used here.

Go to the results page and describe the results.

What is your conclusion about whether this puzzle always works? Explain.

Is it possible to try all numbers on the spreadsheet? If not, what are some numbers we can't use in a spreadsheet?

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