OK, let's do this. We've got 5139 and 1138 and we're adding them all together.

Step 1: We'll start by adding the digits 9 & 8 in column 1 and get 17.
We'll write down the last digit 7 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 3 & 3 in column 2 and get 7.

Step 3: We'll start by adding the digits 1 & 1 in column 3 and get 2.

Step 4: We'll start by adding the digits 5 & 1 in column 4 and get 6.

So, 5139 + 1138 = 6277.

