We've got two numbers: 790 and 504. Let's find their sum.

Step 1: We'll start by adding the digits 0 & 4 in column 1 and get 4.

Step 2: We'll start by adding the digits 9 & 0 in column 2 and get 9.

Step 3: We'll start by adding the digits 7 & 5 in column 3 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

So, 790 + 504 = 1294.

