Here we go! We're going to add 2145 and 9172 together.

Step 1: We'll start by adding the digits 5 & 2 in column 1 and get 7.

Step 2: We'll start by adding the digits 4 & 7 in column 2 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

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

Step 4: We'll start by adding the digits 2 & 9 in column 4 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

So, 2145 + 9172 = 11317.

