When the celebrated German mathematician Karl Friedrich Gauss (1777-1855) was nine he was asked to add all the integers from 1 through 100. He quickly added 1 to 100, 2 to 99, and so on for 50 pairs of numbers each adding to 101. 50 X 101=5,050.Now find the sum of all the digits in integers from 1 through 1,000,000,000.That's all the digits in all the numbers, not all the numbers themselves. -Riddles