just move the decimal point where the exponent indicates
there are no negative exponents here so none of these numbers will be decimal:
8. 6430, moved the decimal point 3 places to the right
9. 84560000 moved the decimal point 7 places to the right
10. 800000 (six zeros)
11. 90000000000 (ten zeros)
12. 3.482^9 (I'll use this one as example)
To convert a number to scientific notation, move the point just after the first number from left to right (that is not zero), remove the zeros that are from right to left if there are any (for example, if you have 45002 it is not needed to remove any because there is a significant number is in front of the two zeros, instead, if we have a number like 2046000, the last three zeros are removed).
there you will have the number: 3.482
Then, count how many places the point moved (in the original number) and that will be the exponent
3,482,000,000
moved 9 places
this isn't a decimal number so the exponent will be positive
3.482^9