We've got two numbers: 5504 and 6860. Let's find their sum.

Step 1: We'll start by adding the digits 4 & 0 in column 1 and get 4.

Step 2: We'll start by adding the digits 0 & 6 in column 2 and get 6.

Step 3: We'll start by adding the digits 5 & 8 in column 3 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 5 & 6 in column 4 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

So, 5504 + 6860 = 12364.

