We are presented with 4324 and 3321. Let's work out the sum.

Step 1: We'll start by adding the digits 4 & 1 in column 1 and get 5.

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

Step 3: We'll start by adding the digits 3 & 3 in column 3 and get 6.

Step 4: We'll start by adding the digits 4 & 3 in column 4 and get 7.

So, 4324 + 3321 = 7645.

