How do you change a decimal to scientific notation?

Two examples may help more than a detailed explanation.

Suppose we have .000003567

Move the decimal one place to the right of the first non-zero digit and write:

3.567 x 10^-6    where "6" is the number of places we moved the decimal to the right

Now suppose we have 3567

Again, move the decimal one place to the right of the first non-zero digit and write:

3.567 x 10³      where "3" is the number of places we moved the decimal to the left

So....moving the decimal to the right results in a negative exponent on 10. And moving it to the left results in a positive exponent on 10.

Hope that helps.