小学六年级数学比例单元测试卷

（满分：100分 考试时间：60分钟）

姓名：__________     学号：__________     班级：__________

完成时间：_______ 分钟     得分：_______

题号	一	二	三	四	总分
分数

注意事项：

1. 答题前请先填写姓名、学号和班级。

2. 请用黑色签字笔答题，保持卷面整洁。

3. 选择题和填空题请将答案直接写在题中横线上；计算题和应用题需写出必要的解题过程。

4. 本试卷主要考查比例的基本概念、计算及应用。

一、选择题（每题5分，共15分）

1. 下列各组比中，能与 $\frac{1}{3} : \frac{1}{4}$ 组成比例的是（ ）。
A. $3 : 4$     B. $4 : 3$     C. $12 : 9$     D. $9 : 12$

2. 已知 $3 : 5 = 9 : x$，那么 $x$ 的值是（ ）。
A. $10$     B. $12$     C. $15$     D. $20$

3. 一幅地图的比例尺是 $1 : 5000000$，表示地图上 $1$ 厘米的距离相当于实际距离（ ）。
A. $5$ 千米     B. $50$ 千米     C. $500$ 千米     D. $5000$ 千米

二、填空题（每空5分，共10分）

1. 在一个比例中，两个外项互为倒数，其中一个内项是 $\frac{2}{5}$，则另一个内项是（ ）。

2. 如果 $a$ 与 $b$ 的比值是 $0.8$，那么 $a : b =$ （ ） $:$ （ ）。

三、计算题（共40分）

1. （12分）解比例： $2.5 : x = 0.5 : 1.2$。

解：

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