Here we go! We're going to add 2590 and 9111 together.

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

Step 2: We'll start by adding the digits 9 & 1 in column 2 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 5 & 1 in column 3 and get 7.

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, 2590 + 9111 = 11701.

