Here we go! We're going to add 8435 and 253 together.

Step 1: We'll start by adding the digits 5 & 3 in column 1 and get 8.

Step 2: We'll start by adding the digits 3 & 5 in column 2 and get 8.

Step 3: We'll start by adding the digits 4 & 2 in column 3 and get 6.

Step 4: We'll start by adding the digits 8 & 0 in column 4 and get 8.

So, 8435 + 253 = 8688.

