Given, 137 + 276 = 435 Adding units digits i.e., 7 + 6 = 13, but given as 5, which is 13 - 8 and also 1 is carry forwarded to the tens digit. i.e., + 1 Here, 7 + 3 + 1 = 1 i.e., 11 - 8 = 3 and 1 is carry forwarded to hundred digits Now, the sum of digits in hundred's place is 1 + 1 + 2 = 4 ie., Using the same logic, we have Using digits sum 1 + 2 = 3 Tens digits sum = 3 + 7 = 10 i.e., 10 - 2 and + 1 carry forward Hundreds digits sum = 1 + 7 + 6 = 14 i.e., 14 - 8 = 6 and one carry forward.