*This is orders of magnitude*

Question

1)So, I have to estimate 16,700,000,000,000,000 the product of a single digit of 10.
- 2 x 10^16
- 2 x 10^15 *my answer*
- 1 x 10^16
- 1 x 10^15

2)0.00000394 estimated as the product of a single digit.
____ x 10____ *fill in the blanks* *my answer 3.94 x 10^6

3)Finding numbers are greater than 3 × 10^−7?
- 9 * 10^-9 *my answer*
- 2 x 10^-5
- 6 x 10^-7 *my answer*
- 5 x 10^-8
- 2 x 10^-7
4) best order of magnitude for 58,000
- 10^3 *my answer*
- 10^4
- 10^5
- 10^6

5)best order of magnitude estimate for 0.00003?
- 10^-3
- 10^-4
- 10^-5 *my answer*
- 10^-6
~I am having a difficult time with these problems! Please help, thanks!