We are presented with 9121 and 4361. Let's work out the sum.

Step 1: We'll start by adding the digits 1 & 1 in column 1 and get 2.

Step 2: We'll start by adding the digits 2 & 6 in column 2 and get 8.

Step 3: We'll start by adding the digits 1 & 3 in column 3 and get 4.

Step 4: We'll start by adding the digits 9 & 4 in column 4 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

So, 9121 + 4361 = 13482.

