Mark's First Calculators

Plastic Chinese abacus
I bought this abacus in San Francisco's China Town while on a family vacation during the summer before 4th grade. By the time we got home I knew how to use it to add, subtract, multiply and divide.

This is a Chinese style abacus called a suanpan. The Japanese style, called a soroban, only has 1 bead on the top and 4 on the bottom.
  Here are some links to good abacus sites: Abacus: Mystery of the Bead
Wikipedia more than you wanted to know about abacus history.
[more to come...]
Pickett N515-T slide rule
I recieved a slide rule like this one as part of a mail order radio/electronics course I received as a Christmas present when I was in sixth grade. It was stolen and destroyed sometime during junior high. During high school I bought a better one which I still have. I've collected a few slide rules over the years; you can see the collection here.

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