大拇指宽约1 一片树叶的面积约30
0.49×0.990.49 0.99×2.012.01
0.323÷0.80.323 32.6÷2.5326÷25
0.05×0.8= 8.4÷21= 3.5+5.8= 1.25×0.7×0.8=
5.8+4.4= 9.6-4.6= 4.8÷6= (8.8-3.2)÷7=