Scientific notation Scientists often deal with very large numbers, and often with very small numbers. For example, light may pass through a window in 1/100 000 000 000 of a second, and writing so many numbers in complicated calculations can easily lead to mistakes. Very large and very small numbers can be expressed as a factor multiplied by some power of 10. For example, 1 000 000 can be expressed as 106, which is 10X10X10X10X10X10X10. Just to make sure you understand, 2835 million meters can be written as 2835 X 10 6 meters.