We are presented with 2120 and 2306. Let's work out the sum.

Step 1: We'll start by adding the digits 0 & 6 in column 1 and get 6.

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

Step 3: We'll start by adding the digits 1 & 3 in column 3 and get 4.

Step 4: We'll start by adding the digits 2 & 2 in column 4 and get 4.

So, 2120 + 2306 = 4426.

