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El primer proyecto que sugerimos sería simplemente repetir el cálculo que mostramos,  usando una o más de las aplicaciones que ofrecen las ceibalitas.

Luego, podría ser resolver otros problemas:

- Dados siete de los ocho dígitos en una cédula,  calcular el faltante.

- Siempre que haya un error,  ¿nos dará mal el cálculo del dígito de control? Justificar la respuesta.

- Si transponemos dos dígitos consecutivos,  un error muy frecuente, ¿cambiará el dígito de control calculado?  ¿Podremos darnos cuenta en ese caso,  cuál fue el error y corregirlo?

- ¿Hay otras aplicaciones de los dígitos de control en el mundo real,  además de la cédula de identidad?

Para los que quieran profundizar en el tema y hacer otros ejercicios,  con gusto les enviaremos el trabajo de Omar Gil y Ricardo Vilaró,  que mencionamos en la tabla de cálculo adjunta.

English Text:

We believe this could be an interesting subject for a project using some of the applications in the Plan Ceibal computers.

All of us who live in Uruguay must have, from the age of 45 days,  our ID Card containing our name, picture, signature, finger print, date of birth and a number that identifies us for the rest of our lives.

These are some of the many uses for the ID card:

- To be able to receive Plan Ceibal´s computer.  The plan maintains a database where each computer they have delivered is associated to a student or an educator.

- To have a personal account with BPS, Banco de Previsión Social.  Anyone working in Uruguay may present the ID card and check that BPS is properly crediting the social benefits that person is entitled to receive. 

- As ID to travel to countries in our region,  instead of a passport.

Quite frequently we are asked for our ID card number to fill-in a form,  This happens at school, at the work place, at shops, at government and private offices. It is very easy for errors to occur.

The control digit,  this is the eighth digit,  shown to the right of the dash as in this example:

5.555.555-5

might not be the same that may be calculated using the first seven digits.  This is an indication that most probably there was an error when writing down this ID card number.

We have prepared this spreadsheet for those interested in learning how this control digit is calculated: