第七单元 整理与复习数的世界(1)1. 1/2 3/7 3/10 2/7 2/7 4 7/10 5/32. 3/4 45/7 19/18 2 3/100 15/163. 5/8+7/11+3/8+4/11 4÷4/9-4/9÷4= (5/8+3/8)+(7/11+4/11) =4×9/4-4/9×1/4= 1+1 =9-1/9= 2 =80/9 (2/3-4/9×3/8)÷7/16 5/9×1/6+4/9÷6= (2/3-1/6)×16/7 =5/9×1/6+4/9×1/6= 1/2×16/7 =(5/9+4/9)×1/6= 8/7 = 1×1/6 = 1/64. 化简:6:5 4:3 2:5 8:1 比值:6/5 4/3 0.4 85 |