Not to worry, we've got 5107 and 3561. Let's get to adding them!

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

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 1 & 5 in column 3 and get 6.

Step 4: We'll start by adding the digits 5 & 3 in column 4 and get 8.

So, 5107 + 3561 = 8668.

