Respuesta :

butterisdabest
first you must find the tenths place

7 .8 3 9
O T H Th

So, the 8 is in the tenths place. Now look at the number to it's right, 3.

Since 3 is less than 5, you just turn everything behind the 8, including the 3, into a zero, giving you 7.800 or 7.8