We've got two numbers: 400 and 7926. Let's find their 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 0 & 2 in column 2 and get 2.

Step 3: We'll start by adding the digits 4 & 9 in column 3 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 0 & 7 in column 4 and get 8.

So, 400 + 7926 = 8326.

