Let's solve this addition problem. We have 1456 and 4121, and we need to add them together.

Step 1: We'll start by adding the digits 6 & 1 in column 1 and get 7.

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

Step 3: We'll start by adding the digits 4 & 1 in column 3 and get 5.

Step 4: We'll start by adding the digits 1 & 4 in column 4 and get 5.

So, 1456 + 4121 = 5577.

