Napier's Local Arithmetic Board | STEM Montessori Math Learning Tool

John Napier was a brilliant Scottish mathematician who lived from 1550 to 1617. He developed a number of methods to simplify mathematic operations most notably logarithms but also some calculation tools like Napiers Bones and this Local Arithmetic Board. This board will allow the calculation of 2 numbers, though each number must be less than 512.

It's an amazing thing to use this board and get a sense of the history as well as the mathematics behind it.

The set comes with base, cover, and pegs. The pegs are nice quality cribbage board pegs. The set measures about 7" x 10" with the text deeply laser engraved. Wood shown in picture and video is alder, but may be varied. Peg color may also vary.

Made in our Hudson, Florida shop.

Here is an idea of how it works:

Break down numbers to be multiplied (factors) into their base 2 components. One factor goes on the right hand column and

the other on the bottom row. In the example 24 x 36, the factor 24 is composed of the numbers 16 and 8. Put pegs in the 16 hole and the 8 hole on the right column. The factor 36 is composed of the numbers 32 and 4. Put pegs in the 32 and 4 holes in the bottom row.

Starting on the upper row, move pegs diagonal left and down to the bottom row. Then add the pegs on the bottom row to get the answer. See example below for 24 x 36.

If while moving pegs diagonal, you run into another peg, then you will have 2 pegs on the same spot. The procedure is to move one peg left and discard the other. That is, if 2 pegs were on 256 from the "8" row; then move one peg to 512 and discard the other.

Materials: Wood