Laugh Calculator: Solution (Post #777)

Here’s Calvin with his solution to the Fun with Math: Laugh Calculator.

We picked a number (e.g., 9), multiplied by 2, added 7, multiplied by 50, added 1660 (or 1659, depending on our birthdate), subtracted our four digit year of birth (e.g., 1989) and ended with a 3 digit number: 

9 x 2 = 18 + 7 = 25 x 50 = 1250 + 1660 = 2910 – 1989 = 921

* The first digit = how many times we wanted to laugh out loud (e.g., 9).

* The last two digits = our current age (e.g., 21).

* * * * *

So, how does the Laugh Calculator work?  Here’s Calvin’s solution: 

1. We multiplied the number picked in step 1 by 100: 

e.g., 9 x 2 (step 2) x 50 (step 4) = 900

As a result, the number we picked “magically” becomes the first digit of the three digit number (step 7):  9xx

2.  In step 3, we added 7  to the equation, then multiplied it by 50 (step 4):

7 x 50 = 350

3.  In step 5, we added 1660 (or 1659 for birthdays still to come):

350 + 1660 = 2010 (the current year!)

When you subtract the year you were born from the current year, your age “magically” appears at the last 2 digits of the 3 digit number: 21

And, for those whose birthday has not arrived yet this year, we subtract the year of birth from 2009, instead of 2010.

Stay tuned!  More fun to come!