Standard form is commonly used by mathematicians in writing very large numbers just like using scientific notations. The number 0.00085 is already in its standard form but, if we are going to write its expanded form, it is written this way: expanded form using the fractional form of the number
0 x 1/1 + 0 x 1/10 + 0 x 1/100 + 0 x 10000 + 8 x 1/ 10 000 + 5 x 1/ 100 000
When written in words: zero and eighty-five hundred thousandths.
