Question

22×30
25×40
42×20
47×30
64×40
78×80
78×30
73×60
92×20
84×50 prin descompuner

Answer 1

22×30=
(20+2)×(30+0)=
20×30+20×0+2×30+2×0=
600+0+60+0=
660

25×40=
(20+5)×(40+0)=
20×40+20×0+5×40+5×0=
800+0+200+0=
1000

42×20=
(40+2)×(20+0)=
40×20+40×0+2×20+2×0=
800+0+40+0=
840

47×30=
(40+7)×(30+0)=
40×30+40×0+7×30+7×0=
1200+0+210+0=
1410

64×40=
(60+4)×(40+0)=
60×40+60×0+4×40+4×0=
2400+0+160+0=
2560

78×80=
(70+8)×(80+0)=
70×80+70×0+8×80+8×0=
5600+0+640+0=
6240

78×30=
(70+8)×(30+0)=
70×30+70×0+8×30+8×0=
2100+0+240+0=
2340

73×60=
(70+3)×(60+0)=
70×60+70×0+3×60+3×0=
4200+0+180+0=
4380

92×20=
(90+2)×(20+0)=
90×20+90×0+2×20+2×0=
1800+0+40+0=
1840

84×50=
(80+4)×(50+0)=
80×50+80×0+4×50+4×0=
4000+0+200+0=
4200


Dacă tu crezi că merit, astept coroana!