一个书架上层有180本书，是下层的2倍，书架下层有多少本书？（用方程解）
直接写出得数+=+=﹣0.125=﹣=+0.3= 10﹣=×=×=×= 10×=
口算：﹣=+=×= 25×10%=
直接写得数．﹣= 3+1=×6= 7.43﹣1.4﹣2.6= 1÷= 5.1+0.3= 0÷（﹣）= 25×4= 5.4÷0.3=
直接写得数 2﹣=×= 20%÷=×30%= 3.5+1.5= 0.5×=
直接写出得数+= 1÷0.25= 3.14×8= 6.3×= 2.4÷=×= 80×40%= 21÷=﹣×5=×18×=
+
=
+
=
﹣0.125=
﹣
=
+0.3=
=
×
=
×
=
×
= 10×
=
﹣
=
+
=
×
= 25×10%=
﹣
= 3+1
=
×6= 7.43﹣1.4﹣2.6= 1÷
=
﹣
）= 25×4= 5.4÷0.3=
=
×
= 20%÷
=
×30%= 3.5+1.5= 0.5×
+
=
= 2.4÷
=
×
= 80×40%= 21÷
=
﹣
×5=
×18×
=
粤公网安备 44130202000953号