①一袋牛奶245
②教室的空间大约是150
③小玉的腰围约60
④卫生间地面的面积约12
1-0.23= 1.3×0.2= + = - = × =
÷ = 125×42= 6π≈ 1-30%= ×7÷ =
① + ÷
②( - )÷
③ × ÷
④(6.9-3.15)÷0.3×0.8
⑤7.2×[(7.8+ )÷0.4]