We have numbers 7021 and 2751. Let's start adding them together.

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

Step 2: We'll start by adding the digits 2 & 5 in column 2 and get 7.

Step 3: We'll start by adding the digits 0 & 7 in column 3 and get 7.

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

So, 7021 + 2751 = 9772.

