﻿ ﻿﻿﻿ 分数、小数、百分数%、+ – × / | 玄数
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分数、小数、百分数%、+ – × /

2015-05-16

SAT

Jerry, Will, Al all work at the same company. Jerry earns 80% of Will’s salary, and Will earns 75% of Al’s salary. What percent of Al’s salary is equal to Jerry’s salary?

A. 80%
B. 75%
C. 70%
D. 65%
E. 60%
E. Jerry, Will, Al都在同一家公司工作. Jerry获得的薪资是Will的80％, 而Will获得的薪资是Al的75％. Al的薪资的百分之几等于杰瑞的?

一、分数 Fraction

 1 — X 分子用 a（one），分母用X的序数词 1 — 2 a half 1 — 4 a quarter 1 —— 100 a（one）hundredth

 A — B （A > 1）—— 分子A用基数词，分母B用序数词再 + s ，整数 and 分数 2 — 3 two thirds 4 — 5 four fifths 5 2 — 7 five and two sevens

二、小数 Decimal

0.1 —— zero point one

123.123 —— one hundred and twenty-three point one two three

三、 百分数 Percentage

% —— percent ：

5% —— five percent

0.123 %—— zero point one two three percent

四、 + – × /

1. +  plus / add ：2 + 10 = ？ 2 + 10 = 12

How much is two plus ten?
Two plus ten is twelve.

2.  –  minus ： 8 – 5 = ？  8 – 5 = 3

How much is eight minus five?
Eight minus five is three.

3.  ×  times / mutiplied by ： 2 × 3 = ？  2 × 3 = 6

How much is two times three.?
Two times three is six.

4.  / divided by ： 10 / 4 = ？ 10 / 4 = 2.5

How much is ten divided by four?
Ten divided by four is two point five.

练习

A fraction whose denominator is some power of 10, usually indicated by a dot (decimal point or point) written before the numerator: as 0.4 = 4/10; 0.126 = 126/1000.
 * 基数词、序数词 * 时间、日期 * 倍数

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