Question

2.5x(40+0.8)x1.25的简便计算

Answer 1

可不能把40与2.5先乘,0.8与0.125乘

2.5x(40+0.8)x1.25

=2.5×40.8×1.25

=2.5×4×10.2×1.25

=10×10.2×1.25

=102×1.25

=127.5