- 
  
  His calculator used gears and levers to add and subtract numbers.
- 
  
  It can solve more than one math proplem.
- 
  
  This machine used only 1s and 0s to solve math problems.
- 
  
  It was big as two small houses and weighed 30 tons
- 
  
  The Mark1 was as long as half a football field.