We've got two numbers: 4323 and 257. Let's find their sum.

Step 1: We'll start by adding the digits 3 & 7 in column 1 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 2 & 5 in column 2 and get 8.

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

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

So, 4323 + 257 = 4580.

