Abacus

Dec 20, 2020

I sketched and added count.

I'll sketch by an abacus of 7 digits (in a mobile area, 5 digits) and solve a problem of count.
When it's tilted, a ball is even swept from raku and it's made a zero, it begins.
A tap make the problem indication area indication of an arrow and nondisplay at the time of on of an assist, please.
It can be chosen whether it's a problem including a subtraction.
It can be established variously from a setup button.