The answer is 9801. To solve this without a calculator, visualise a 100 * 100 square, which has 10,000 elements. You want to remove one row and one column from this square. Removing a row subtracts 100, and removing a column after that subtracts 99. The result is a 99*99 square. So the result is 10000 - 100 - 99 = 9801 .