Scientific notation is used to express very large or very small numbers. A number in scientific notation is written as the product of a number (integer or decimal) and a power of 10. The number has one digit to the left of the decimal point. The power of ten indicates how many places the decimal point was moved.

The number 6x10^-6 could be converted to the fraction 6/1000000 because the exponent would indicated that the denominator would have 6 decimal places.

The number 6.5x10^-5 could be converted to the fraction 6.5/100000. This could be converted to 65/1000000 by multiplying the numerator and denominator of the fraction by 10.

A scientific notation number with a negative exponent can be converted to a fraction be adding zeros to the denominator. The number of zeros will be the absolute value of the exponent.