6點(diǎn)3乘以零點(diǎn)九九加二點(diǎn)零一怎樣簡(jiǎn)便運(yùn)算？

題目里沒(méi)加明白是否有括號(hào)，如果是6.3*0.99+2.01則等于6.3*（1-0.01）+2.01＝6.3*1-6.3*0.01+2.01＝6.3-0.063+2.01＝8.247
如果是6.3*（0.99+2.01）＝6.3*3＝18.9

6.3×0.99+2.1
=6.3×(1-0.01)+2.1
=6.3×1-6.3×0.01+2.1
=(6.3+2.1)-0.063
=8.4-0.063
=8.337