《2025年口算训练四年级数学下册人教版升级版》

照样子写算式。
$17\times40 = 40\times17$
$13\times70 =$
$50\times700 =$
$60\times80 =$
$70\times30 =$
$209\times8 =$
$30\times54 =$
$39\times20 =$
$520\times2 =$
$307\times8 =$
$290\times8 =$
$25\times40 =$
$250\times40 =$
$503\times8 =$
$290\times7 =$
$12\times30 =$
$6\times42 =$
$11\times24 =$
$8\times15 =$
$a\times b =$

答案：

照样子写算式。
$38\times25\times4 = 38\times(25\times4)$
$35\times2\times5 = 35\times(2\times\_\_)$
$(4\times82)\times25 = 82\times(\_\_\times25)$
$(6\times25)\times4 = 6\times(\_\_\times4)$
$(125\times5)\times8 = (\_\_\times\_\_)\times5$
$(3\times4)\times5\times6 = (\_\_\times\_\_)\times(\_\_\times\_\_)$
$42\times125\times8 =$
$125\times17\times8 =$
$(25\times125)\times(8\times4) =$
$38\times125\times8\times3 =$
$125\times32 =$
$125\times32\times4 =$
$4\times87\times25 =$
$125\times37\times8 =$
$25\times17\times4 =$
$(4\times8)\times(125\times25) =$
$8\times125\times8\times3 =$
$125\times8\times13 =$
$20\times34\times5 =$
$50\times123\times2 =$

答案：