The expression is
.
\ \ \
Place value chart for 104 and 82.
\\

Line up the decimal points and draw a line below the numbers.
\
First find the difference of the ones digit.
\The difference of the ones digit =
.
\

Next find the difference of the tens digit.
\Notice that it is not possible to subtract 8 tens from 0 tens.
\So, 1 unit must be borrowed from hundreds column.
\The difference of the tens digit =
.

Next find the difference of the hundreds digit.
\The difference of the hundreds digit =
.
\

\
The difference is
.