Except that for checks, it's not the numerical part written in the little box that matters, it's the full written amount e.g. 'Five Thousand Three Hundred Fourt

Except that for checks, it's not the numerical part written in the little box that matters, it's the full written amount e.g. 'Five Thousand Three Hundred Fourty-Seven and 33/100' for 5,347.33. Similar rationale, though, because it's easier to modify a number (say, change a 7 to a 9) than to change a full word.