Sure thing! We've got 990 and 4155 and we're gonna add them together.

Step 1: We'll start by adding the digits 0 & 5 in column 1 and get 5.

Step 2: We'll start by adding the digits 9 & 5 in column 2 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 9 & 1 in column 3 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

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

So, 990 + 4155 = 5145.

