Question

donovan is going to add many numbers. each number will use only the digit 1. what is the greatest number of addends donovan can use without having to regroup?

Answer 1

1+1+1+1+1+1+1+1+1=9 . Adding 1 together 9 times gives you the highest possible sum without having to regroup.

Adding 1 together 10 times gives you a product of 10 which would make you have to regroup.

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