Twenty addition problems a sheet, both amounts written one above the other with the decimal points aligned. Carrying works exactly as it does with whole numbers - the only new thing is that a carry out of the cents column is a carry into the dollars.
That is the whole difficulty, and it is worth being explicit about: $2.85 + $1.40 is the same arithmetic as 285 + 140, just written with a point in it. Students who can do the second and not the first are usually losing the alignment, not the addition.
Line the decimal points up, add the cents column and carry into the dollars if it reaches 100, then add the dollars. Keeping the points aligned is most of it.
Set Amounts to Under $100 for problems that carry across three columns.
Turn on Include Answer Pages and a matching key prints behind each worksheet page, with the problems in the same order and every answer written to the cent.
Yes - the Subtracting Money page, which orders each pair so no answer is ever negative.