Question

二点五乘四点八有几种简便方法计算

Answer 1

2.5x4.8=2.5x(4+0.8)
=10+2
=12;
2.5x4.8=(5/2)x(24/5)
=24/2
=12;
2.5x4.8=2.5x4x1.2
=1x1.2
=1.2.