课程： 6.2混合数字四舍五入到最接近的整数

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选择节混合数字四舍五入到最接近的整数

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混合数字四舍五入到最接近的整数
Frank thinks he will need at about $\begin{aligned} 12 \frac{1}{4} \end{aligned}$ pounds of sand for a sandbox he is building. The sand he wants is $3 per pound. About how much will Frank spend on sand? Estimate the amount of sand he will need to the nearest whole number.
::弗兰克认为他需要大约1214磅的沙子来建造他正在建造的沙箱。他想要的沙子是每磅3美元。关于弗兰克在沙子上要花多少钱?估计他需要的沙子数量将达到最近的整数。

In this concept, you will learn how to round mixed numbers to the nearest whole number.
::在此概念中,您将学会如何将混合数字舍入到最近的整数。

Round Mixed Numbers to the Nearest Whole
::最接近整批的圆形混合数

You can also estimate by rounding mixed numbers . A mixed number is a number that has a whole number and a fraction. It refers to a value that is between two whole numbers .
::您也可以通过四舍五入混合数字来估计。混合数字是一个数字,它包含一个整数和一个分数。它指的是两个整数之间的数值。

When rounding decimal numbers to the the nearest whole number, you look at the number in the tenths place. If the number less than 5, round down. If the number is greater than or equal to 5, round up. Five tenths can be written into a fraction as $\begin{aligned} \frac{5}{10} \end{aligned}$ or $\begin{aligned} \frac{1}{2} \end{aligned}$ .
::当将十进制数舍入到最近的整数时,请查看十分位数中的数字。如果数字小于5,则四舍五入。如果数字大于或等于5,则四舍五入。十分之五可以写成分数为5 10或12。

To round mixed numbers to the nearest whole number, look at the fraction part of the mixed number. If the fraction is less than , round down to the nearest whole number. If the fraction is greater than or equal to $\begin{aligned} \frac{1}{2} \end{aligned}$ , round up to the nearest whole number.
::要将数字组合到最接近的整数,请查看混合数的分部分。如果分数小于 ,则四舍五入到最接近的整数。如果分数大于或等于 12,则将整数组合到最接近的整数。

Here is a mixed number.
::这是混合数字。

$\begin{aligned} 5 \frac{1}{6} \end{aligned}$

Compare the fraction to $\begin{aligned} \frac{1}{2} \end{aligned}$ . The equivalent fraction for $\begin{aligned} \frac{1}{2} \end{aligned}$ in terms of sixths is $\begin{aligned} \frac{3}{6} \end{aligned}$ .
::将分数比作 1 2 。按六分之一计算,十二分之一的等值分数是 3 6 。

$\begin{aligned} \frac{1}{6} < \frac{1}{2} \end{aligned}$

Round the mixed number down to the nearest whole number. $\begin{aligned} \frac{1}{6} \end{aligned}$ is less than $\begin{aligned} \frac{1}{2} \end{aligned}$ .
::组合数的四舍五入到最近的整数。16小于12。

$\begin{aligned} 5 \frac{1}{6} \approx 5 \end{aligned}$

$\begin{aligned} 5 \frac{1}{6} \end{aligned}$ rounds down to 5.
::5,1,6发子弹向下到5发

Examples
::实例

Example 1
::例1

Earlier, you were given a problem about Frank's sandbox project.
::之前,你对弗兰克的沙箱项目有意见

Frank will need about $\begin{aligned} 12 \frac{1}{4} \end{aligned}$ pounds of sand that costs $3 per pound. Round the mixed number to a whole number and multiply to find the estimate price of the sand.
::弗兰克需要1214磅的沙子,每磅要3美元。

First, compare the fraction to $\begin{aligned} \frac{1}{2} \end{aligned}$ . $\begin{aligned} \frac{1}{2} \end{aligned}$ of a whole divided into 4 parts is $\begin{aligned} \frac{2}{4} \end{aligned}$ .
::首先,将分数比作12。 1,2,一个整体分为4个部分,2,4个部分。

$\begin{aligned} \frac{1}{4} < \frac{2}{4} \end{aligned}$

Then, round the mixed number to the nearest whole number.
::然后,将混合数折为最近的整数。

$\begin{aligned} 12 \frac{1}{4} \approx 12 \end{aligned}$

Next, multiply the number of pounds by the price per pound, $3.
::接下来,乘以磅数乘以每磅3美元的价格。

$\begin{aligned} $ 3 \times 12 = $ 36 \end{aligned}$

Frank will spend about $36 on the sand.
::弗兰克会在沙子上花费36美元

Example 2
::例2

Sarah is helping to measure a hem on a dress. She measures that the dress needs to be shortened $\begin{aligned} 6 \frac{12}{16} \end{aligned}$ inches. Given this measurement, does it make sense for Sarah to round down to 6 or up to 7 inches?
::Sarah帮助测量着装的血脉。她测量着装需要缩短 6 12 16 英寸。根据这种测量,Sarah 切到 6 或 7 英寸是合情合理的吗?

First, compare the fraction to $\begin{aligned} \frac{1}{2} \end{aligned}$ . $\begin{aligned} \frac{1}{2} \end{aligned}$ of a whole divided into 16 parts is $\begin{aligned} \frac{8}{16} \end{aligned}$ .
::首先,将分数比作12。 1,2,一个整体分为16个部分,8,16个部分。

Then, round the mixed number to the nearest whole number. $\begin{aligned} \frac{12}{16} \end{aligned}$ is greater than $\begin{aligned} \frac{1}{2} \end{aligned}$ .
::然后,将混合数四舍五入到最近的整数。 12 16 大于12。

$\begin{aligned} 6 \frac{12}{16} \approx 7 \end{aligned}$

$\begin{aligned} 6 \frac{12}{16} \end{aligned}$ rounds up to 7.
::6 12 16发,最多7发

Sarah should round up and shorten the dress by about 7 inches.
::Sarah应该围起来把裙子缩短7英寸

Example 3
::例3

Round this mixed number: $\begin{aligned} 7 \frac{6}{9} \end{aligned}$ .
::这一轮的混合人数:7 6 9 。

First, compare the fraction to $\begin{aligned} \frac{1}{2} \end{aligned}$ . $\begin{aligned} \frac{1}{2} \end{aligned}$ of a whole divided into 9 parts is between 4 and 5 ninths.
::首先,将分数比作12.1、2,将整体分为9个部分,即4至5分九分之四至5分之九。

$\begin{aligned} \frac{6}{9} > \frac{5}{9} \end{aligned}$

Then, round the mixed number to the nearest whole number. $\begin{aligned} \frac{6}{9} \end{aligned}$ is greater than $\begin{aligned} \frac{1}{2} \end{aligned}$ .
::然后,将混合数四舍五入到最近的整数中。 6 9 大于12。

$\begin{aligned} 7 \frac{6}{9} \end{aligned}$ rounds up to 8.
::7,6,9发,8发

Example 4
::例4

Round this mixed number: $\begin{aligned} 4 \frac{1}{4} \end{aligned}$ .
::圆形这一混合数: 4, 1, 4 。

First, compare the fraction to $\begin{aligned} \frac{1}{2} \end{aligned}$ . $\begin{aligned} \frac{1}{2} \end{aligned}$ of a whole divided into 4 parts is $\begin{aligned} \frac{2}{4} \end{aligned}$ .
::首先,将分数比作12。 1,2,一个整体分为4个部分,2,4个部分。

$\begin{aligned} \frac{1}{4} < \frac{2}{4} \end{aligned}$

Then, round the mixed number to the nearest whole number. $\begin{aligned} \frac{1}{4} \end{aligned}$ is less than $\begin{aligned} \frac{1}{2} \end{aligned}$ .
::然后,将混合数四舍五入到最近的整数。 14小于12。

$\begin{aligned} 4 \frac{1}{4} \end{aligned}$ rounds down to 4.
::4 4 4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4 发4

Example 5
::例5

Round this mixed number: $\begin{aligned} 6 \frac{5}{10} \end{aligned}$ .
::这一轮的混合人数:6 5 10。

First, compare the fraction to $\begin{aligned} \frac{1}{2} \end{aligned}$ . $\begin{aligned} \frac{1}{2} \end{aligned}$ of a whole divided into 10 parts is $\begin{aligned} \frac{5}{10} \end{aligned}$ .
::首先,将分数比作12。 1,2,一个整体分为10个部分,为5,10。

$\begin{aligned} \frac{5}{10} = \frac{5}{10} \end{aligned}$

Then, round the mixed number up to the nearest whole number. $\begin{aligned} \frac{5}{10} \end{aligned}$ is equal to $\begin{aligned} \frac{1}{2} \end{aligned}$ .
::然后,将混合数绕到最近的整数。 5 10等于12。

$\begin{aligned} 6 \frac{5}{10} \end{aligned}$ rounds up to 7.
::6 5 10发,最多7发

Review
::回顾

Round each number to the nearest whole number.
::将每个数字四舍五入到最近的整数中。

$\begin{aligned} 3 \frac{8}{10} \end{aligned}$

$\begin{aligned} 1 \frac{2}{3} \end{aligned}$

$\begin{aligned} 5 \frac{5}{6} \end{aligned}$

$\begin{aligned} 6 \frac{4}{13} \end{aligned}$

$\begin{aligned} 11 \frac{5}{7} \end{aligned}$

$\begin{aligned} 26 \frac{5}{9} \end{aligned}$

$\begin{aligned} 14 \frac{2}{11} \end{aligned}$

$\begin{aligned} 13 \frac{1}{10} \end{aligned}$

$\begin{aligned} 17 \frac{6}{13} \end{aligned}$

$\begin{aligned} 19 \frac{4}{7} \end{aligned}$

$\begin{aligned} 21 \frac{11}{12} \end{aligned}$

$\begin{aligned} 34 \frac{12}{25} \end{aligned}$

$\begin{aligned} 46 \frac{16}{24} \end{aligned}$

$\begin{aligned} 21 \frac{18}{20} \end{aligned}$

$\begin{aligned} 9 \frac{19}{30} \end{aligned}$

Review (Answers)
::回顾(答复)

章节大纲

常规

混合数字四舍五入到最接近的整数

Round Mixed Numbers to the Nearest Whole ::最接近整批的圆形混合数

Examples ::实例

Example 1 ::例1

Example 2 ::例2

Example 3 ::例3

Example 4 ::例4

Example 5 ::例5

Review ::回顾

Review (Answers) ::回顾(答复)

Round Mixed Numbers to the Nearest Whole
::最接近整批的圆形混合数

Examples
::实例

Example 1
::例1

Example 2
::例2

Example 3
::例3

Example 4
::例4

Example 5
::例5

Review
::回顾

Review (Answers)
::回顾(答复)