Question

14.56-2.99 13.45-3.19-2.81 （15.2-9.9 ）-（4.3-2.540 ）的简便算法

Answer 1

14.56-2.99

=14.56-3+0.01

=11.56+0.01

=11.57

13.45-3.19-2.81

=13.45-(3.19+2.81)

=13.45-6

=7.45

（15.2-9.9 ）-（4.3-2.540 ）

=15.2-10+0.1-(4.3-2.54)

=5.2+0.1-4.3+2.54

=5.3-4.3+2.54

=1+2.54

=3.54