可以简单算出0.24×1.2×1500.8×0.9÷0.8×0.99×4.38 . 12×98+8.12×26.4×(0.65438+

=(0.24×30)×(1.2×5)

=7.2×6

=43.2

0.8×0.9÷0.8×0.9

=(0.8÷0.8)×(0.9×0.9)

=1×0.81

=0.81

9.9×4.3

=10×4.3-0.1×4.3

=43-0.43

=42.57

8.12×98+8.12×2

=8.12×(98+2)

=8.12×100

=812

6.4×(0.125+12.5)

=0.8×8×(0.125+12.5)

=0.8×(8×0.125+8×12.5)

=0.8×(1+100)

=0.8×1+0.8×100

=0.8+80

=80.8

4.2×75÷25

=4.2×(75÷25)

=4.2×3

=12.6