6.5*4.8*12.5简便计算=6.5x8x0.6x12.5=（6.5x0.6）x（8x12.5）=3.9x100=390
6.5x4.8x12.5=6.5x6x0.8x12.5=（6.5x6）x（0.8x12.5）=39x10=390
6.5*4.8*12.5=6.5*2*8*0.3*12.5=6.5*2*8*12.5*0.3=13*100*0.3=13*30=390
