主要内容
五年级（美国）
课程: 五年级（美国） > 单元 4
课程 2: 展开式的小数复习展开式的小数
复习用展开形式表达小数并做一些练习题.
展开形式
数的展开式利用这个数中每一位数的数位表示出该数.
使用数位顺序表可以知道一个数中每一位数的数位.
例题
请写出 start color #11accd, 3, end color #11accd, point, start color #7854ab, 4, end color #7854ab, start color #1fab54, 0, end color #1fab54, start color #ca337c, 5, end color #ca337c 的展开式.
| 整数 | . | 一位小数 | 两位小数 | 三位小数 |
|---|---|---|---|---|
| start color #11accd, 3, end color #11accd | . | start color #7854ab, 4, end color #7854ab | start color #1fab54, 0, end color #1fab54 | start color #ca337c, 5, end color #ca337c |
3, point, 405, equals, start color #11accd, 3, end color #11accd, start text, space, 个, 1, end text plus, start color #7854ab, 4, end color #7854ab, start text, space, 个, 0, point, 1, end text, plus start color #1fab54, 0, end color #1fab54, start text, space, 个, 0, point, 01, end text, plus, start color #ca337c, 5, end color #ca337c, start text, space, 个, 0, point, 001, end text
empty space, equals, left parenthesis, start color #11accd, 3, end color #11accd, times, 1, right parenthesis, plus, left parenthesis, start color #7854ab, 4, end color #7854ab, times, start fraction, 1, divided by, 10, end fraction, right parenthesisplus, left parenthesis, start color #1fab54, 0, end color #1fab54, times, start fraction, 1, divided by, 100, end fraction, right parenthesis, plus, left parenthesis, start color #ca337c, 5, end color #ca337c, times, start fraction, 1, divided by, 1000, end fraction, right parenthesis
3, point, 405 的展开式是 start color #11accd, 3, end color #11accd, plus, start color #7854ab, start fraction, 4, divided by, 10, end fraction, end color #7854ab, plus, start color #ca337c, start fraction, 5, divided by, 1000, end fraction, end color #ca337c.
想更多地了解数的展开式,请点击 视频.