Alrighty, so, If I remember correctly: I believe the answer you're looking for is 5.76 x 10^3
Imagine there's a decimal after the zero. You can only have one integer in FRONT of the decimal therefore you move your decimal 3 places to the left. This gives you 5.76 x 10^3 because you always remove the zero when it's at the end of the number.
Hope this helps!