We are presented with 2903 and 4952. Let's work out the sum.

Step 1: We'll start by adding the digits 3 & 2 in column 1 and get 5.

Step 2: We'll start by adding the digits 0 & 5 in column 2 and get 5.

Step 3: We'll start by adding the digits 9 & 9 in column 3 and get 18.
We'll write down the last digit 8 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 2 & 4 in column 4 and get 7.

So, 2903 + 4952 = 7855.

