1.25×0.64＝1.25×（0.8×0.8）＝1.25×0.8×0.8=（1.25×0.8）×0.8＝1×0.8＝0.8
1.25×0.64=1.25×8×0.08=10×0.08=0.8
1.25×0.64＝1.25×0.8×0.8＝1×0.8＝0.8
1.25×0.64，＝1.25×（0.8×0.8），去括号，得＝1.25×0.8×0.8，＝1×0.8，＝0.8
