75．如图所示，大正方形的面积比小正方形的面积多1O平方厘米．求两正方形之间的圆面积．
直接写得数．+= += ﹣= 1﹣= ﹣=0.25+= += 2+= += ﹣=
脱式计算，能简算的要简算．3﹣﹣++﹣+﹣．
①+= ②+= ③﹣=④2﹣= ⑤+= ⑥+=
下面各题怎样算简便就怎样算．6﹣﹣．
直接写得数．﹣= ﹣= += +=+= ﹣= ﹣= 0.3+=
+
+
= 
﹣
= 1﹣
= 
﹣
=
= 
+
= 2+
= 
+
= 
﹣
=
﹣
+
+
﹣
+
﹣
．
+
+
= ③
﹣
=
= ⑤
+
= ⑥
+
=
﹣
．
﹣
= 
﹣
= 
+
= 
+
=
+
= 
﹣
= 
﹣
= 0.3+
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