Dan Romero
@dwr.eth
How does the German method work? 25 * 65 = 1,625 25 65 5 * 5 = 25 (2 * 6) + 5 = 17 1,725 What am I missing?
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dusan
@ds8
generally it doesn't, given two double digit integers ab and cd, this method works only when 10*d = c*(a + b)
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dusan
@ds8
correction, it's 10*d = a*d + b*c so d*(10 - a) = b*c
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