Răspuns:
a)
54 x 8=(50+4)×8
=50×8+4×8
=400+32
=432
63 x 7=(60+3)×7
=60×7+3×7
=420+21
=441
418 x 7=(400+10+8)×7
=400×7+10×7+8×7
=2800+70+56
=2870+56
=2926
b)
512 x 9=(500+10+2)×9
=500×9+10×9+2×9
=4500+90+18
=4590+18
=4608
224 x 3=(200+20+4)×3
=200×3+20×3+4×3
=600+60+12
=660+12
=672
219×4=(200+10+9)×4
=200×4+10×4+9×4
=800+40+36
=840+36
=876
826 x 5.=(800+20+6)×5
=800×5+20×5+6×5
=4000+100+30
=500+30
=530