OK, let's do this. We've got 4259 and 2710 and we're adding them all together.

Step 1: We'll start by adding the digits 9 & 0 in column 1 and get 9.

Step 2: We'll start by adding the digits 5 & 1 in column 2 and get 6.

Step 3: We'll start by adding the digits 2 & 7 in column 3 and get 9.

Step 4: We'll start by adding the digits 4 & 2 in column 4 and get 6.

So, 4259 + 2710 = 6969.

