Metoda mersului invers se refera la rezolvarea problemei de la sfarsit spre inceput , dar se schimba operatiile :
opreeratia de adunare se schimba in scadere
operatia de scadere se schimba in adunare
operatia de inmultire se schimba in impartire
operatia de impartire se schimba in inmultire
Ex.
n+10-20+5=45
n+10-20=45-5
n+10-20=40
n+10=40+20
n+10=60
n=60-10
n=50
Ex.
(nx10+16):6-10=56
(nx10+16):6=56+10
(nx10+16):6=66
(nx10+16)=66x6
nx10+16=396
nx10=396-16
nx10=380
n=380:10
n=38
