



 
Julie, There is no ``simple'' way, it is a puzzle to make you think about subtraction. My first thought is that the leftmost digit of the five digit number must be a 3 if there is no borrowing, or a 4 if there is borrowing. The simplest hypothesis is no borrowing: 3****  **** = 33333. The simplest solution would be digitwise, with no borrowing at all: So, some borrowing has to occur, which means that the digits will be matched in pairs with a difference of At this point, what helps is to make a diagram, linking pairs of digits that cannot be matched: 1 cannot be matched to 2, 3, 6, 9, and 2 cannot be matched to 1, 3, 4, 7 ... There we begin to see that we could match 2 and 5, 6 and 9, 7 and 3 and 1 and 8; the remaining number is 4, which would have to be the leftmost digit of the 5 digit number. It almost works, but not quite. with 41597  8263, we get 33334, but if we force a borrow from 7, as in 47159  3826, we don't borrow from 4 anymore, so we get 43333. Can you see how to fix it? Claude  


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