Sometimes it is necessary to use very large and very small numbers. These can best be indicated and handled in calculations by use of scientific notation, which is to say by use of exponents. Use of scientific notation requires writing the number so that it is the result of multiplying some whole number power of 10 by a number between 1 and 10. Examples are:
1234 = 1.234 × 10³

0.01234 = 1.234 × 1/100 = 1.234 × 10⁻²

0.001234 = 1.234 × 1/1000 = 1.234 × 10⁻³

To convert a number to its equivalent in scientific notation:
Place the decimal point to the right of the first non-zero digit. This will now be a number between 1 and 9.
Multiply this number by a power of 10, the exponent of which is equal to the number of places the decimal point was moved. The exponent is positive if the decimal point was moved to the left, and negative if it was moved to the right. For example:
1,234,000.0 × 0.000072/6000.0 = 1.234 × 10⁶× 7.2 × 10 ⁻⁵/6.0 × 10³

Now, by simply adding or subtracting the exponents of ten, and remembering that moving an exponent from the denominator of the fraction to the numerator changes its sign,
= 1.234 × 10⁶ × 10 ⁻⁵ × 10 ⁻³ × 7.2/6 = 1.234 × 10⁻² × 7.2/6

Now, dividing by 6,
= 1.234 × 10⁻² × 1.2 = 1.4808 × 10⁻² = 1.4808/100 = 0.014808

The last operation changed 1.4808 × 10⁻² into the final value, 0.014808, which is not expressed in scientific notation.