數學題中一

用四舍五入，舍入至十位
１６２０x３０
＝４８６００

worng answer!!!! use 1600x25 is easier and more accurate. and the question said that use 相容數字法 it is clearly that the correct answer is use 40x40x25=40x1000=40000

1617 x 25.1
=40586.7

1620*25
=40500

１６１７×２５.１
＝４０５８６．７

1617x25.1
約1600x25
＝40000

48600

=40586.7

2007-01-25 22:46:21 補充：
=40590not=40586.7

=48600

48600

４１９４２．１