fNBookForm2 prints a number in Textbook Form with powers abbreviations in place of exponents (default). Output is a compressed dressed form textbooks use for significant figures tables. Easy, quality, comprehensive. booknum reads such.
an important aspect is that the result maintains both accuracy and precision and has rounding control. doing this sometimees requires careful planning (error-prone complicated conversions).
can read them back from textbook (into Mathematica) preservingly...