We are presented with 7511 and 2310. Let's work out the 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 & 1 in column 2 and get 2.

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

Step 4: We'll start by adding the digits 7 & 2 in column 4 and get 9.

So, 7511 + 2310 = 9821.

