4 Answers

10^4= 1/10^4 = 0.0001
5×0.0001=0.0005
Source(s): My Brain. 
Your number is in scientific notation. The power of ten tells you how far and in what direction to move the decimal point on the 5.
So when you move the decimal point 4 spaces to the left (left for a negative power, right for a positive power) you’ll get .0005

.0005 = 5 ten thousandths
Here are some powers of 10 that should help you understand:
(the ^ symbol is “Raised to the power of”)
10^4 = 10000 = ten thousand
10^1 = 10
10^0 = 1
10^1 = .1
10^4 = .0001 = 1 ten thousandth

the number is expressed in scientific notation
which is also equal to 0.0005
it like saying divide 5 by ten 4 times. ( because exponent is negative multiply if positive)