3. Phép nhân hai số tự nhiên. Dạng 1. Tính một cách hợp lý

$14.50$$=7.\left(2.50\right)$$=7.100$=700

$16.125$$=2.\left(8.125\right)$$=4.1000$=4000

$9.24.25$$=\left(9.6\right).\left(4.25\right)$

$=54.100$$=5400$

$30.40.50.60$

$=30.\left(20.2\right).50.60$

$=\left(30.2.60\right).\left(20.50\right)$

$=3600.1000$$=3600000$

$27.36+27.64$

$=27.\left(36+64\right)$$=27.100$$=2700$

$25.37+25.63-150$

$=25.\left(37+63\right)-150$

$=25.100-150$

$=2500-150$

$=2350$

$425.7.4-170.60$

$=\left(425.4\right).7-170.60$

$=1700.7-\left(170.10\right).6$

$=1700.7-1700.6$

$=1700.\left(7-6\right)$=1700

$8.9.14+6.17.12+19.4.18$

$=\left(8.9\right).14+\left(6.12\right)+\left(4.18\right).19$

$=72.14+72.17+19.72$

$=72.\left(14+17+19\right)$$=72.\text{\hspace{0.17em}}50$

$=3600$