We have numbers 2443 and 521. Let's start adding them together.

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

Step 2: We'll start by adding the digits 4 & 2 in column 2 and get 6.

Step 3: We'll start by adding the digits 4 & 5 in column 3 and get 9.

Step 4: We'll start by adding the digits 2 & 0 in column 4 and get 2.

So, 2443 + 521 = 2964.

