Question

用简便计算。 0.79x2.5x0.4要过程 25x3.2x1.25 0.56x101 54.6X

Answer 1

0.79x2.5x0.4

=0.79x(2.5x0.4)

=0.79x1

=0.79

25x3.2x1.25

=25x4x0.8x1.25

=(25x4)x(0.8x1.25)

=100x1

=100

0.56x101

=0.56x100+0.56x1

=56+0.56

=56.56

54.6X101-54.6

=54.6x(101-1)

=54.6x100

=5460

12.5x2.59x0.8

=12.5x0.8x2.59

=10x2.59

=25.9