已知图中正方形的周长是28厘米，求平行四边形的面积是多少？
350×0.02= 1﹣25%= 1+15%= 12﹣7.9=
×
=
﹣
=（
﹣）×24= 16×
=
131131÷131=
×
×0= 1÷
﹣÷1= 12.5×0.08=
0.9+99×0.9= 7.8×0.25×4=
﹣
+
= 0.52×100=
×8+8×
=
×21×
= 98﹣0.23﹣0.77=
+÷=
44÷
= 9300÷5÷6= 0÷
= 1997+1998+1999+6=
直接写出得数．
4+4.73= 
÷9= 
×
÷×= 4 
﹣4 
=
375÷1 
= 
×2÷×2= 36+0.4= 5×32×2.5=
1÷0.9= 8×（12+0.5）= 
= 
= 
= 
= 
= 
= 
= 
= 
= 
= 
= 
= 
= 
=
35+0.4= 8×（12+0.5）= 4×0.8×2.5×12.5= 
= 
= 
= ．
直接写出得数．
1﹣0.09=0.45×101= 2÷0.02= 0.25×0.7×0.4=
×
= 5﹣
=
÷
= 2.72+3﹣2.72+3=
直接写出得数．
1.9+3.01= 0.23×400=
÷
= 5×
÷×5=
（
+
）×15=
×
×
=﹣
= 10﹣
﹣0.875=
水结成冰后，体积增加了
，当冰融化水后，体积减少几分之几？