The expression is
.
Place value chart for 3.2 and 1.4.
\ 
Line up the decimal points and draw a line below the numbers.
\Annex zero to align the numbers.
\
First find the sum of the tenths digit.
\The sum of the tenths digit
.

Next find the sum of the ones digit.
\The sum of the ones digit
.
\

The sum is 4.6.