We've got two numbers: 6105 and 720. Let's find their sum.

Step 1: We'll start by adding the digits 5 & 0 in column 1 and get 5.

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

Step 3: We'll start by adding the digits 1 & 7 in column 3 and get 8.

Step 4: We'll start by adding the digits 6 & 0 in column 4 and get 6.

So, 6105 + 720 = 6825.

