The expression is 
Place value chart for 32 and 8.
\ 
Line up the decimal points and draw a line below the numbers.
\
First find the addition of the ones digit.
\The addition of the ones digit =
.
The sum is 10, so carry digits to the next column on the left
\ \
Next find the addition of the tens digit.
\The addition of the tens digit =
.

The difference is 40.