4. * 10^-9
4. * 10^10
6. * 10^7
4. * 10^-8
All rounded to the nearest whole number. Take the number given and move the decimal point to make the number less that 10 but greater than 1. The, count how many spaces you moved the decimal point, this will be the power of 10. If you moved the decimal point to the left, the power of 10 will be positive. If you moved it to the right, the power of 10 will be negative. Hope this helped!
