We've got two numbers: 6402 and 72. Let's find their sum.

Step 1: We'll start by adding the digits 2 & 2 in column 1 and get 4.

Step 2: We'll start by adding the digits 0 & 7 in column 2 and get 7.

Step 3: We'll start by adding the digits 4 & 0 in column 3 and get 4.

Step 4: We'll start by adding the digits 6 & 0 in column 4 and get 6.

So, 6402 + 72 = 6474.

