一根绳子用去2.3米，还剩下1.8米，这根绳子原来有多长．
直接写出得数． 3=== 0.3×0.2= 5﹣=== 4﹣（）=
请选择合适的方法计算下面各题．﹣+ 1﹣﹣﹣+++﹣﹣+﹣．
下面各题，怎样算简便就怎样算． ①++ ②1﹣﹣ ③+﹣．
直接写出得数．========
口算.====
=
=
= 0.3×0.2=
=
=
= 4﹣（
）=
﹣
+
1﹣
﹣
﹣
+
+
+
﹣
﹣
+
﹣
．
+
+
②1﹣
﹣
③
+
﹣
．
=
=
=
=
=
=
=
=
=
=
=
=
粤公网安备 44130202000953号