Ready to do some math? We're starting with 1221 and 2375 and adding them up.

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

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

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

Step 4: We'll start by adding the digits 1 & 2 in column 4 and get 3.

So, 1221 + 2375 = 3596.

