Paraguay Cédula + RUC calculation

ruc_calc.js

/*
    To calculate the RUC number for your cedula:
    Starting with the rightmost digit, multiply it by 2.
    Then, multiply the next digit by 3 and add it to the first result.
    Then, multiply the next digit by 4 and add it to the running total.
    ... keep doing this.
    Finally, take the remainder of the the total divided by 11 (called the modulo), 
    and subtract it from 11.

    original inspiration: http://www.necesitomas.com/digito-verificador
*/

// TEST
const cedula = '8765432'; // RUC: 8765432-6
const digits = cedula.split("").reverse().map(x => parseInt(x));

let total = 0;
digits.forEach((digit, index) => {
    total += digit * (index + 2);
});

console.log('RUC:', `${cedula}-${11 - total % 11}`);

https://www.jybaro.com/blog/cedula-de-identidad-ecuatoriana/ Example for Ecuador