We've got two numbers: 4054 and 3453. Let's find their sum.

Step 1: We'll start by adding the digits 4 & 3 in column 1 and get 7.

Step 2: We'll start by adding the digits 5 & 5 in column 2 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 0 & 4 in column 3 and get 5.

Step 4: We'll start by adding the digits 4 & 3 in column 4 and get 7.

So, 4054 + 3453 = 7507.

