Răspuns:
4×985=4×(900+80+5)=4×900+4×80+4×5=3600+320+20=3940
7×578=7×(500+70+8)=7×500+7×70+7×8=3500+490+56=4046
9×349=9×(300+40+9)=9×300+9×40+9×9=2700+360+81=3141
6×894=6×(800+90+4)=6×800+6×90+6×4=4800+540+24=5364
8×584=8×(500+80+4)=8×500+8×60+8×4=4000+480+32=4512