# make a sum with cards

Take the numbered diamond cards in a standard deck, that is those from 2 to 10. You may use some of them to form a sum: for example 23+45=68. What is the maximum result you may obtain? I hoped there was some way to obtain 10xy, but this seems not to be the case.

• Can you specify what the allowed actions are, please? Can we for example form the number 9876543210? Aug 12 '18 at 9:43
• A single number is not a sum. You must have one or more plus signs.
– mau
Aug 12 '18 at 9:51
• answer is hidden in this answer of this question [ here](puzzling.stackexchange.com/questions/53684/…).
– Oray
Aug 12 '18 at 10:14
• @Oray Here we are not limited to the sum of two numbers and each number is not limited to three digits. If you have a formal proof that 1098 is the biggest number we can get in this puzzle, I think this would make a very interesting answer. Aug 12 '18 at 11:24
• @xhienne i did not refer that part, just gave an answer from another perspective :) no other intention.
– Oray
Aug 12 '18 at 11:25

$623+475=1098$ and $746+352=1098$