You know that this number has to be 4 digits and have a 1 in the thousands place. The other three digits (the 2 digits to the far right have to be the same) have to add up to 13. Meanwhile, you know that the digit in the hundreds place cannot be greater than 2. If it is 2, then you would subtract that from 13 to get 11. But that does not work because 11 is odd, and the other 2 digits could not be the same. So subtract 1 and get 12. 12 /2 =6, so the other 2 digits would be 6’s. So the number is 1166.