Once you learn the basics of scientific notation questions are pretty straight forward but questions that have zeros in front of number’s really stump me up. Questions like . When you do scientific notation, you take the comma and move it after the first actual number. You count how many times you moved the comma and write it as an exponent of 10. With numbers like above, you would do the same thing. Take the comma, move it after the very first real number then count how many times you moved it. But it wouldn’t be a positive exponent, it would be a negative. So the answer to the above question is 3.9×10^-3.