We have numbers 2110 and 6521. Let's start adding them together.

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

Step 2: We'll start by adding the digits 1 & 2 in column 2 and get 3.

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 2 & 6 in column 4 and get 8.

So, 2110 + 6521 = 8631.

