丽丽跑了450米，奶奶跑的米数相当于丽丽跑的2倍，妈妈跑的比丽丽和奶奶跑的总数还多850米。妈妈跑了多少米？
直接写出下面各题得数． 15×=﹣=+=×25%= 7÷=÷=÷10=×= 1÷÷=÷×=
直接写出得数．×=+=÷= 1﹣=÷3= 8×25%=÷=﹣20%=
直接写出得数： 9÷= ；÷= ；×= ；×0÷= ．
直接写得数×=×= 21×= 6÷= 10÷=+0.5= 1﹣= 2÷0.2=÷=：=
直接写出得数． 100÷10%= 12÷= 6.3÷0.07= 10﹣=÷22=+=×=÷=×= 24×=
=
﹣
=
+
=
×25%= 7÷
=
÷
=
÷10=
×
= 1÷
÷
÷
×
=
×
=
+
=
÷
= 1﹣
=
÷3= 8×25%=
÷
=
﹣20%=
= ；
÷
×
= ；
×0÷
= ．
×
=
×
= 21×
= 6÷
=
=
+0.5= 1﹣
= 2÷0.2=
÷
=
：
=
= 6.3÷0.07= 10﹣
=
÷22=
+
=
×
=
÷
=
×
= 24×
=
粤公网安备 44130202000953号