Not to worry, we've got 3971 and 8106. Let's get to adding them!

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

Step 2: We'll start by adding the digits 7 & 0 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 3 & 8 in column 4 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

So, 3971 + 8106 = 12077.

