1.25×2.5×6.4=1.25×2.5×(4×8×0.2)=(1.25×8)×(2.5×4)×0.2=10×10×0.2=20
1.25×2.5×6.4
=1.25×2.5×(4×8×0.2)
=(1.25×8)×(2.5×4)×0.2
=10×10×0.2
=20
