OK, let's do this. We've got 5776 and 7742 and we're adding them all together.

Step 1: We'll start by adding the digits 6 & 2 in column 1 and get 8.

Step 2: We'll start by adding the digits 7 & 4 in column 2 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 7 & 7 in column 3 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 5 & 7 in column 4 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

So, 5776 + 7742 = 13518.

