## Identification numbers with check digit algorithms

### Instructions

1. Move green dots, with mouse, to "write" the first fifteen digits of the visa card number. For example, in case $$1234\;\;5678\;\; 9012\;\;345$$, we have to place the dots in the following manner:

2. The orange dot indicates the checksum digit of visa card. In the example in the figure above, it is equal to $$2$$.