求教数学巧算题48x25x67=?{125x6}x16=?299x99+99=?404x25=?12x25x70=?

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/06 18:49:45

求教数学巧算题48x25x67=?{125x6}x16=?299x99+99=?404x25=?12x25x70=?
求教数学巧算题
48x25x67=?
{125x6}x16=?
299x99+99=?
404x25=?
12x25x70=?

求教数学巧算题48x25x67=?{125x6}x16=?299x99+99=?404x25=?12x25x70=?
48x25x67=8x4x25x67=(4x25)x(8x67)=100x536=53600
(125x6)x16=(125x6)x8x2=(125x8)x6x2=1000x12=12000
299x99+99=299x99+1x99=(299+1)x99=300x99=29700
404x25=(400+4)x25=400x25+4x25=10000+100=10100
12x25x70=3x4x25x70=(4x25)x(3x70)=100x210=21000