What to do when the batteries in your calculator run out and there are too many buttons to press to get to the calculator app on your mobile device? I know, no one can figure out things in their head anymore. Reach for one of the oldest calculating devices called an abacus. Lucky you just happens to be wearing the one you made. Watch the waiter or waitress look on in amazement as you calculate their tip.
This abacus ring is based on a traditional Chinese abacus(suanpan), 2 top + 5 bottom bead configuration. Works for decimal and also hexidecimal numbers. There are stories of people that can do complex calculations on an abacus faster than another person using an electronic calculator.
Pinky ring not for you? Try the slide rule bangle bracelet
instead. DISCLAIMER: Not yet approved for use on SATs or any other standardized testing.