What is the standard form of the decimal number 0.00034?

Any number that can be written as a decimal number, between 1.0 and 10.0, multiplied by a power of 10, is said to be in standard form.

$0.00034=\frac{34}{100000}$

$=\frac{3.4\times 10}{{10}^5}$

$=3.4\times 10\times {10}^{-5}$

$=3.4\times {10}^{1-5}$       [$\because {\mathrm{a}}^{\mathrm{m}}\times {\mathrm{a}}^{\mathrm{n}}={\mathrm{a}}^{\mathrm{m}+\mathrm{n}}$]

$=3.4\times {10}^{-4}$

Therefore, the standard form of the decimal number 0.00034 is $3.4\times {10}^{-4}$.