Adding machine, available on the collection of Matemateca IME-USP
Exhibit made by Estes Objethos Atelier, video by <a href="//commons.wikimedia.org/wiki/User:Rodrigo.Argenton" title="User:Rodrigo.Argenton">Rodrigo.Argenton</a>, presentation and script by Eduardo Colli.
CC BY-SA 4.0
Matemateca (IME/USP), provided via digitalization project by the volunteer:<a href="//commons.wikimedia.org/wiki/User:Rodrigo.Argenton" title="User:Rodrigo.Argenton">Rodrigo Tetsuo Argenton</a>. Music Money by Jahzzar, available at <a rel="nofollow" class="external text" href="http://freemusicarchive.org/music/Jahzzar/Sketches/money_1311">Free Music Archive</a>.