Tính. 72 × 30 = …………. 230 × 70 = ………... 63 × 40 = ………….. 2 050 × 70 = ………. 85 × 60 = ………… 7 400 × 50 = ……..
Giải thích
72 × 30 = (72 × 3) × 10 = 216 × 10 = 2 160 230 × 70 =(23 × 7) × 100 = 161 × 100 = 16 100 | 63 × 40 = (63 × 4) × 10 = 252 × 10 = 2 520 2 050 × 70 =(205 × 7) × 100 = 1 435 × 100 = 143 500 | 85 × 60 = (85 × 6) × 10 = 510 × 10 = 5 100 7 400 × 50 =(74 × 5) × 1 000 = 370 × 1 000 = 370 000 |