Use a superscript for exponents, such as 10⁻³
Use the minus sign before the exponent to make the number smaller
Use scientific notation for very small numbers, such as 3.2 × 10⁻⁵
Use decimal notation with leading zeros, such as 0.00042
Use a subscript only if you mean an index, not a small number
On a keyboard, use the symbol menu or formatting tools to insert superscript characters
In plain text, type the number normally with zeros after the decimal point
In math or word processors, apply superscript formatting to the exponent part