Dividing By Zero With The ‘Facit ESA-01’

The mathematics of the ‘Facit ESA-01 mechanical calculator’; don’t divide by zero.


Infinity is not a real number. It’s a concept. In Calculus class I learned about upper bounds and lower bounds; limits. Infinity is a big deal in Maths because it’s a big deal in reality – Sort of.

Anyway, I came across one cool machine not too long ago, and it used a simple math principle to divide numbers: division is a mega-system of subtraction. A whole value, x that is the result of a number, a divided by b is the number of times that b can be subtracted from a to give 0. Sometimes it gets really close to zero but it never gets there. in other words,

(a/b) = x = [#t ] (10 - 5) ~ 0

It is this principle that the Facit ESA-01 uses to divide. And unlike modern calculators that display an error message when you try to divide a number by zero, ESA tries to commit suicide. Continue reading “Dividing By Zero With The ‘Facit ESA-01’”