Before electronic calculators and even desktop computers, there was the mechanical calculator, a device used to perform automatically the basic operations of arithmetic. Most mechanical calculators were comparable in size to small desktop computers and have been rendered obsolete by the advent of the electronic calculator. The top image above shows what they looked like when the shell was removed. Click here to view the first image in this week’s demotivational poster gallery. Continue reading for a viral video of plane passengers in Siberia who decided to give their frozen aircraft a little push.