We are presented with 4028 and 1406. Let's work out the sum.

Step 1: We'll start by adding the digits 8 & 6 in column 1 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 2 & 0 in column 2 and get 3.

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

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

So, 4028 + 1406 = 5434.

