/\1/10 too.
Wikipedia.com says:
A vulgar fraction is said to be a proper fraction if the absolute value of the numerator is less than the absolute value of the denominator — that is, if the absolute value of the entire fraction is less than 1 — but an improper fraction (US) or top heavy fraction (British) if the absolute value of the numerator is greater than or equal to the absolute value of the denominator.
Put simply, 10/10 IS NOT A PROPER FRACTION, THEREFORE YOU ARE BOTH WRONG. Now shut up and stop arguing about it.