We are presented with 90 and 552. Let's work out the sum.

Step 1: We'll start by adding the digits 0 & 2 in column 1 and get 2.

Step 2: We'll start by adding the digits 9 & 5 in column 2 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 0 & 5 in column 3 and get 6.

So, 90 + 552 = 642.

