Explain how the value of the 7 in 327,902 will charge if you move it to the tens place

It will change because you will move it back, so instead of being in the thousands place, (being 7,000) it will be in the tens place. (being 70)

The 7 is currently in the thousands place, so the number currently reads three hundred twenty- seven thousand, nine hundred two. 
If you move the seven to the tens place the number becomes smaller and then reads three hundred twenty thousand, nine hundred seventy- two. 
You lost seven thousand from the first option, but yet gained seventy in the second option.