Sure thing! We've got 1521 and 8450 and we're gonna add them together.

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

Step 2: We'll start by adding the digits 2 & 5 in column 2 and get 7.

Step 3: We'll start by adding the digits 5 & 4 in column 3 and get 9.

Step 4: We'll start by adding the digits 1 & 8 in column 4 and get 9.

So, 1521 + 8450 = 9971.

