Scientific notation is a way to write very large or small numbers as a product of a number between 1 and 10 and a power of 10. To convert a number to scientific notation, the decimal is moved to place one non-zero digit before the decimal point, and the number of places the decimal is moved determines the exponent of 10. Numbers greater than 1 have positive exponents, while numbers less than 1 have negative exponents. Converting back to standard form moves the decimal right for positive exponents and left for negative exponents by the value of the exponent.