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标题: terminating decimal [打印本页]

作者: belle98    时间: 2012-1-11 20:26
标题: terminating decimal
N是正整数,N/225是terminating decimal

*1, N dividable by 3

*2, N dividable by 5

我也不太明白啥叫terminating decimal(是否解作无限不循环小数?), 觉得可能是可以除尽,不会有循环小数吧,225是9的倍数,所以两个都不行,选了E
是否正确,請指导

作者: 宣小妞妞妞    时间: 2012-1-11 20:28
这道题我今天考了!!!

terminating decimal是有限小数。。
作者: misterbloom    时间: 2012-1-15 22:15
terminating decimal 就是有限小数的意思,请记住能被N个2或N个5除的都是terminating decimal
作者: cherryin    时间: 2012-1-15 23:45
那我理解这题选B
作者: Gmatliu    时间: 2012-1-16 09:56
我觉得是E。 因为225分解有两个5, 两个3. 必须被两个3整除N/225才能是terminating decimal
Terminating and Repeating Decimals

Any rational number (that is, a fraction in lowest terms) can be written as either a terminating decimal or a repeating decimal. Just divide the numerator by the denominator. If you end up with a remainder of 0, then you have a terminating decimal. Otherwise, the remainders will begin to repeat after some point, and you have a repeating decimal.


Example:

Convert the fraction 5/8 to a decimal.

The division is as follows:



So, 5/8 = 0.625. This is a terminating decimal.


Example:

Convert the fraction 7/12 to a decimal.

The division is as follows:



So:



This is a repeating decimal.

The bar over the number, in this case 3, indicates the number or block of numbers that repeat unendingly




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