Răspuns :
600:8=75
75:3=25
525+25=550
550:5=110
720-110=610
610:9=67
9:9=1
9x1=9
9-9=0
220+0=220
220-20=200
200x0=0
75:3=25
525+25=550
550:5=110
720-110=610
610:9=67
9:9=1
9x1=9
9-9=0
220+0=220
220-20=200
200x0=0