## Tuesday, April 13, 2010

### We just call it math

This blog is really about psychology. We just call it math.

When you eat lunch or dinner out with other people, there is always a chance to show off your math skills by dividing up the check among the diners.

Of course, some people insist on having accurate breakdowns of their specific dish, including the drinks, and bickering about setting the tip, etc. If you take this to extremes, it damages relationships. Quickly. Or you demand separate checks, which is a hassle for the server. But your group trusts one another, and you eat out regularly, it's easiest to just divide evenly.

Here at Ansmar Publishers, home of Excel Math, we use the even division approach. We take the bill and divide it amongst the number of diners. We don't miss an opportunity to poke fun at each other if one of us orders a particularly extravagant dish. Or steal some fries.

Today we went to Filippi's Pizza Grotto. They offer some of the best deals in town. The check for 4 of us looked like this:

\$5.80 lasagna
\$5.50 submarine sandwich
\$5.50 submarine sandwich
\$7.80 pepperoni pizza
\$5.85 ice tea (3 x 1.95)
30.45 subtotal 1
2.66 tax
33.11 subtotal 2
4.89 tip (15% of \$33)
38.00 total

Divided by 4 = \$10 per person.

The sandwich guys might argue that they had a \$5.50 sandwich that turned into a \$10 lunch, but that's the way it goes.

Jim (our business manager) takes the extra 2 dollars back to the office and puts it into the "cookie fund" jar, where it sits until we have a birthday to celebrate. Then the money is spent on cake and ice cream (never cookies).