the expected result was 1.5(3div 2). But instead we got 0.01
Huh? DFSORT's DIV returns an integer value. +3,DIV,+2 would give 1 as the result. I don't know why you say you got 0.01 unless you edited the result of 1 to get that. If you want a result with one decimal place, you need to multiply by +10 and then divide by +2, e.g. (+3,MUL,+10),DIV,+2 would give a result of 15 which you could then edit to 1.5.