Place values left of decimal: ... hundreds, tens, ones.

Place values right of decimal: tenths, hundredths, thousandths.

Break down 30.794 by place value:
3	=	tens (30)
0	=	ones (0)
7	=	tenths (0.7)
9	=	hundredths (0.09)
4	=	thousandths (0.004)
The digit 9 is in the hundredths place.