I found an error in this spreadsheet: in the sheet name "primes ^ (1/3)", '/' - invalid character. If you export to xlsx , document will be corrupted. But you can replace all references in formulas and it will be good.
+ google doc has error in HEX2Dec function :
B1 cell formula: "=HEX2Dec(B2)"
B2 cell is empty
result : #ERROR!, Ms Excel returns 0.
Funny I never thought of using a spreadsheet as a stepping debugger :)
Time for euclid's division
Way back when, I used a spreadsheet to implement some digital signal processing algorithms for a class I was taking. It found it significantly aided in understanding.
I saw the video and that was quite amazing. However, this spreadsheet seems pretty broken right now.