Đề bài

Bài 1(1.23). Thực hiện các phép nhân sau:

a) 951 . 23;

b) 47 . 273 ;

c) 845 . 253;

d) 1 356 . 125.

Lời giải chi tiết

a) \(\begin{array}{*{20}{r}}{951}\\{x꧑\quad \quad }\\{23}\\\hline{2853}\\{1902\,\;}\\\hline{21873}\end{array}\)    951 . 23 = 21 873.

 

b) \(\begin{array}{*{20}{r}}{273}\\{x\quad \quad }\\{47}\\\hline{1911}\\{1092\,\;}\\\hline{12831}\end{array}\)   47 . 273 = 12 831.

c) \(\begin{array}{*{20}{r}}{845}\\{x\quad \quad }\\{253}\\\hline{2535}\\{4225\;\,}\\{1690\quad }\\\hline{213785}\end{array}\)845 . 253 = 213 785.d) \(\begin{array}{*{20}{r}}{1356}\\{x\quad \quad }\\{125}\\\hline{6780}\\{2712\;\,}\\{1356\quad }\\\hline{169500}\end{array}\)1 356 . 125 = 169 500.