If you're seeing this message, it means we're having trouble loading external resources on our website.

如果你被网页过滤器挡住,请确保域名*.kastatic.org*.kasandbox.org 没有被阻止.

主要内容

复习分数乘法

复习分数乘法的基础并做一些练习题.

分数的乘法

两个分数相乘,分子乘分子,分母乘分母.
例 1: 分数
empty space, start fraction, 5, divided by, 6, end fraction, times, start fraction, 5, divided by, 7, end fraction
equals, start fraction, 5, times, 5, divided by, 6, times, 7, end fraction
equals, start fraction, 25, divided by, 42, end fraction
例 2:带分数
先将带分数写成假分数.
2, start fraction, 2, divided by, 3, end fraction, times, 1, start fraction, 3, divided by, 5, end fraction
equals, space, start fraction, 8, divided by, 3, end fraction, times, start fraction, 8, divided by, 5, end fraction \qquad
equals, start fraction, 8, times, 8, divided by, 3, times, 5, end fraction
equals, start fraction, 64, divided by, 15, end fraction
把以上假分数写成带分数 4, start fraction, 4, divided by, 15, end fraction .
想要学习更多关于分数相乘的知识,请点击 视频.

约分

约分可以使运算中的数字变小,因此在做分数乘法前要先进行约分.
例题
empty space, start fraction, 3, divided by, 10, end fraction, times, start fraction, 1, divided by, 6, end fraction
equals, start fraction, 3, times, 1, divided by, 10, times, 6, end fraction
equals, start fraction, start cancel, 3, end cancel, start superscript, 1, end superscript, times, space, 1, divided by, 10, times, start cancel, 6, end cancel, start subscript, 2, end subscript, end fraction
equals, start fraction, 1, divided by, 20, end fraction
想要更直观的了解分数乘法,请点击以下视频:
分数相乘:分数模型
分数相乘:数轴

练习

问题1
  • 当前
start fraction, 5, divided by, 8, end fraction, times, start fraction, 7, divided by, 8, end fraction
  • 你的答案是
  • 一个整数,例如 6
  • 一个最简真分数,如 3, slash, 5
  • 一个最简假分数,如 7, slash, 4
  • 一个混合带分数,例如 1, space, 3, slash, 4
  • 一个精确的十进位小数,例如0, point, 75
  • pi 的倍数, 例如 12\ \text{pi} 或 2/3\ \text{pi}$

想要更多此类练习,请点击:
分数的乘法
带分数相乘

想加入讨论吗?

尚无帖子。
你会英语吗?单击此处查看更多可汗学院英文版的讨论.