We are presented with 1240 and 2506. Let's work out the sum.

Step 1: We'll start by adding the digits 0 & 6 in column 1 and get 6.

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

Step 3: We'll start by adding the digits 2 & 5 in column 3 and get 7.

Step 4: We'll start by adding the digits 1 & 2 in column 4 and get 3.

So, 1240 + 2506 = 3746.

