Question

6.43999001 x10 to the eighth power in standard form

Answer 1

All you have to do is move the decimal point to the right 8 times (since it is to the eight power)
That would leave you with the number of 643,999,001

****and for future reference this is the english section lol post your math questions in the correct subject next time ^_^, you'll probably get your question answered faster that way!