1.A.10x40=40
13x1000=13000
36x5=180
238x2=467
B. 689x6=4134
793x8=6344
76x81=6156
39x93=3627.
C.254x32=8128
326x27=8802
135x42=5670
301x14=4214
2.grupam(2x197x5 grupam 2 cu 5 si vom obtine 10x197=1970
50x96x2 = 50 îl grupam cu 2 si obținem 100x96=9600
25x79x4 =grupam 25 cu 4 si obtinem 100x79=7900.
3.A.
b). La prima pui un x.
4.1000+2x(25+52)=1000+2x77=1000+154=. 1154
3000-(2100-20x100):10=3000-(2100-2000) :10=3000- 100:10=3000-10=. 2 990
6x(30x50-24x24)-800=6x(1500-567)-800=6x933-800=5598-800=4798
5.175x4=700-550=150 700+150+175=1025.