numarul /___/___/___/___/
doimea(jumatate) /___/___/ suma=810
patrimea(sfert) /___/
/320/
810-320=490
avem 7 segmente
490:7=70 (patrimeal nr)
70x2=140 (doimea nr.)
70x4=280 (numarul)
proba:
280+(280:2)+(280:4)+320=280+140+70+320=420+70+320=490+320=810