Not sure what you mean by "express" form. But I assume you want the regular form.
4.009x10^-3 is 0.004009. Because 10^-3 means move the decimal to the left 3 digits.
Federal Express
how to express the sum 257 and 431 in decimal form
It is not possible to express a number containing alphabetic characters (nA) in scientific form.
Express the ratio below in its simplest form. 12 : 6
FedEx is the short form for "Federal Express".
4,500,000 is the standard form.
5x4x2x4x3x5x5x4
express
"express" both in noun and verb form does not have a gender in English.
75.0
to express what you have done
cheaters get smart