Digit Standard Abacus Soroban Professional 17 Column (10.2 inch) Math Abacus, Math Calculating Tool with Reset Button for Adults (Cofei)

There are a bunch of abaci on available on this site which are prettier than this one -- fine woods, brass fittings -- but in general they don't work as well. The frame (I ordered the "Cofei" color) is a sturdy black high quality plastic, 28 centimeters (11 inches) long. The beads are plastic, but not molded plastic, Rather the beads were turned on a lathe with a precision hole drilled in the exact center. Molded plastic beads, and most wood beads unless the maker is very careful, vary in fit from bead to bead, which slows you down. The rods on this one are fine grain bamboo (there is a reason why so many slide rules are made of bamboo - it slides smoothly without "catching".) The reset mechanism is well built and works smoothly. If you want something for a display case, look elsewhere. If you want an abacus that works great, this is the one. General advice about abaci: Unless you already know the chinese suanpan system, get a japanese soroban abacus. Each digit on a soroban is 0 to 9. With the chinese saunpan there are 16 values a digit can have. In other words, the soroban uses a base 10 numbering system while the suanpan uses a base 16 numbering system. Of course if you are a collector you will get both as well as the Roman and Russian styles. Also, you don''t need a giant abacus with lots of digits. The reason people use the big ones is so they can do two calculations on the left and right. This is handy if you want to multiply or divide, but abaci suck at that. Use a slide rule instead. If you really want to do two calculations at once get two smaller abaci.

This best features of this Japanese Soroban include the 22 columns which allow simple arithmetic operations on numbers as large as 9.999999999999999999999 x 10^22 or switching to decimal fractions, 1.0 x 10^-22 and the fact that it has a reset button. It is great to demonstrate the meaning of scientific notation.

Some of the beads stick. Otherwise it's great I love it!

Nice.

It’s useful, didn’t really impale me base on previous assumptions , part from size , but eh it works for what I needed for .