We are presented with 505018770 and 8591678240. Let's work out the sum.

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

Step 2: We'll start by adding the digits 7 & 4 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 7 & 2 in column 3 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 8 & 8 in column 4 and get 17.
We'll write down the last digit 7 and carry the 1 to the next column.

Step 5: We'll start by adding the digits 1 & 7 in column 5 and get 9.

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

Step 7: We'll start by adding the digits 5 & 1 in column 7 and get 6.

Step 8: We'll start by adding the digits 0 & 9 in column 8 and get 9.

Step 9: We'll start by adding the digits 5 & 5 in column 9 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 10: We'll start by adding the digits 0 & 8 in column 10 and get 9.

So, 505018770 + 8591678240 = 9096697010.

