4×0.5×0.25 0.4×16×0.25 0.35×99-0.35×9 23.6-4.5÷0.3 11.25÷7.5×2.3 如何简算?

4×0.5×0.25=(4×0.25)×0.5=1×0.5=0.50.4×16×0.25 =(0.4×0.25)×16=0.1×16=1.60.35×99-0.35×9=0.35×(99-9)=0.35×90=31.523.6-4.5÷0.3 =23.6-15=8.611.25÷7.5×2.3=1.5×2.3=3.459.6÷1.2+2.4×51.008÷0.48+3.76（480+160）÷（19+21）98.5-125÷25×12160+240×0.3-9020÷0.5-3.45这些题如何简算呀？拜托啦！！！！！！！！9.6÷1.2+2.4×5=8+12=20（直接计算）1.008÷0.48+3.76=1008÷480+3.76=2.1+3.76=5.86（480+160）÷（19+21）=640÷40=1698.5-125÷25×12=98.5-5×12=98.5-60=38.5160+240×0.3-90=160+72-90=232-90=15220÷0.5-3.45=40-3.45=36.55直接计算就行了