We are presented with 402 and 2505. Let's work out the sum.

Step 1: We'll start by adding the digits 2 & 5 in column 1 and get 7.

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

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 0 & 2 in column 4 and get 2.

So, 402 + 2505 = 2907.

