We've got two numbers: 6911 and 5160. Let's find their sum.

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

Step 2: We'll start by adding the digits 1 & 6 in column 2 and get 7.

Step 3: We'll start by adding the digits 9 & 1 in column 3 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

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

So, 6911 + 5160 = 12071.

