脫式計算（能簡便的用簡便方法）28.8-640%-2.8-4.6 ；；；；；；；；；；；；；；；；；；；；；78×370%+5.3×0.875+7886×75%+14÷43932÷[75%-（716-25%）]（712-37.5%）×24-59.

（1）28.8-640%-2.8-4.6=28.8-6.4-2.8-4.6=28.8-2.8-（6.4+4.6）=26-11=15；（2）78×370%+5.3×0.875+78=0.875×3.7+5.3×0.875+0.875=（3.7+5.3+1）×0.875=10×0.875=8.75；（3）86×75%+14÷43=86×75%+14×75%=（86+14）×75%=100×75%=75；（4）932÷[75%-（716-25%）]=932÷[75%-316]=932÷916=12；（5）（712-37.5%）×24-59.=（712-38）×24-59.=712×24-38×24-59=14-9-59=449.