Comment by chris_wot

There's an amazing scene in "This is Spinal Tap" where Nigel Tufnel had been brainstorming a scene where Stonehenge would be lowered from above onto the stage during their performance, and he does some back of the envelope calculations which he gives to the set designer. Unfortunately, he mixes the symbol for feet with the symbol for inches. Leading to the following:

https://www.youtube.com/watch?v=Pyh1Va_mYWI