Add the binary numbers 100101 and 101001 and convert them to decimal (they are unsigned integers). What are possible issues when adding the numbers?

The result is 1001110, which converted is 78. The problem that can occur is overflow, since original number is 6 digit, but result is 7, which may cause to drop the most significant bit and become 14 instead.

The result can be arrived by adding all the numbers together from the right side towards left and carrying over if both of them are 1. Conversion is done from right to left by adding all the numbers starting by 1 multiplying by 2 for every digit count and multiplying by the value itself, so 10+121+ 1221+....