问题解决模型比较

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Comparison of Problem-Solving Models
::问题解决模型比较

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In this section, we will use the problem solving methods learned in the last Concept. We will also compare the methods of “Making a Table” and “Looking for a Pattern” by using each method in turn to solve a problem.
::在本节中,我们将使用在最后一个概念中所学到的解决问题的方法,并将通过使用每一种方法解决问题,比较“制表”和“寻找模式”的方法。

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Original Versus Sale Price
::原始比苏斯销售价格

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A coffee maker is on sale at 50% off the regular ticket price. On the “Sunday Super Sale” the same coffee maker is on sale at an additional 40% off. If the final price is $21, what was the original price of the coffee maker?
::咖啡制造商以正常票价50%的价位出售咖啡。 在“ 星期天超市 ” 上,同一个咖啡制造商以另外40%的价位出售咖啡。 如果最终价格是21美元,咖啡制造商的原价是多少?

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Solution
::解决方案

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Step 1: Understand
::第1步:理解

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We know: A coffee maker is discounted 50% and then 40%. The final price is $21.
::我们知道:咖啡制造商被折扣50%,然后被折扣40%。最后的价格是21美元。

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We want: The original price of the coffee maker.
::我们希望:咖啡制造商的原始价格。

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Step 2: Strategy
::步骤2:战略

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Let’s look at the given information and try to find the relationship between the information we know and the information we are trying to find.
::让我们看看给定的信息, 试着找到我们所知道的信息与我们所试图找到的信息之间的关系。

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50% off the original price means that the sale price is half of the original or $\begin{array}{r}0.5\times \end{array}$ original price.
::50%的原价意味着销售价是原价的一半,或0.5×原价的一半。

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So, the first sale price $\begin{array}{r}=0.5\times \end{array}$ original price
::所以,第一个销售价格=0.5x原始价格

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A savings of 40% off the new price means you pay 60% of the new price, or $\begin{array}{r}0.6\times \end{array}$ new price.
::从新价格中节省40% 意味着你支付新价格的60%, 也就是0.6×新价格。

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$\begin{array}{r}0.6\times (0.5\times \text{original price})=0.3\times \text{original price}\end{array}$ is the price after the second discount.
::0.6x(0.5x原价)=0.3x原价是第二次折扣后的价格。

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We know that after two discounts, the final price is $21.
::我们知道,经过两次折扣后,最后价格为21美元。

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So $\begin{array}{r}0.3\times \text{original price}=\mathrm{\$}21\end{array}$ .
::所以0.3x原价=21美元。

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Step 3: Solve
::步骤3:解决

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Since $\begin{array}{r}0.3\times \text{original price}=\mathrm{\$}21\end{array}$ , we can find the original price by dividing $21 by 0.3.
::由于0.3×原价=21美元,我们能找到原价,将21美元除以0.3。

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$\begin{array}{r}\text{Original price}=\mathrm{\$}21÷0.3=\mathrm{\$}70\end{array}$ .
::原价21美元=0.3美元=70美元。

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The original price of the coffee maker was $70.
::咖啡机的最初价格是70美元。

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Step 4: Check
::第4步:检查

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We found that the original price of the coffee maker is $70.
::我们发现咖啡机的原价是70美元

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To check that this is correct, let’s apply the discounts.
::让我们使用折扣来检查是否正确。

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50% of $\begin{array}{r}\mathrm{\$}70=.5\times \mathrm{\$}70=\mathrm{\$}35\end{array}$ savings. So the price after the first discount is $\begin{array}{r}\text{original price}-\text{savings}\end{array}$ or $\begin{array}{r}\mathrm{\$}70-35=\mathrm{\$}35\end{array}$ .
::70美元=5x70美元=35美元的节省额的50%,第一个折扣后的价格是原价格-节省额,即70-35美元=35美元。

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Then 40% of that is $\begin{array}{r}.4\times \mathrm{\$}35=\mathrm{\$}14\end{array}$ . So after the second discount, the price is $\begin{array}{r}\mathrm{\$}35-14=\mathrm{\$}21\end{array}$ .
::其中40%是4x35美元=14美元。因此,在第二次折扣后,价格为35-14美元=21美元。

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The answer checks out.
::答案检查出来。

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Receiving Cash
::现金实收现金

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Andrew cashes a $180 check and wants the money in $10 and $20 bills. The bank teller gives him 12 bills. How many of each kind of bill does he receive?
::安德鲁兑现了180美元的支票 想要10美元和20美元的钞票 银行出纳给他12张账单

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Solution
::解决方案

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Method 1: Making a Table
::方法1:编制表格

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Understand
::理解

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Andrew gives the bank teller a $180 check.
::安德鲁给银行出纳员180美元的支票

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The bank teller gives Andrew 12 bills. These bills are a mix of $10 bills and $20 bills.
::银行出纳给安德鲁12张帐单 这些帐单包括10张帐单和20张帐单

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We want to know how many of each kind of bill Andrew receives.
::我们想知道 安德鲁收到多少帐单

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Strategy
::战略战略战略战略 战略战略战略 战略

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Let’s start by making a table of the different ways Andrew can have twelve bills in tens and twenties.
::让我们先列出一张表格, 列出安德鲁在数十年和二十年中 十二张钞票的不同方式。

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Andrew could have twelve $10 bills and zero $20 bills, or eleven $10 bills and one $20 bill, and so on.
::安德鲁可以有十二张10美元的帐单和零张20美元的帐单, 或者十一张10美元的帐单和一张20美元的帐单,等等。

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We can calculate the total amount of money for each case.
::我们可以计算每个案子的总金额

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Apply strategy/solve
::应用战略/解决方案

$10 bills	$ 20 bills	Total amount
12	0	$\begin{array}{r}\mathrm{\$}10(12)+\mathrm{\$}20(0)=\mathrm{\$}120\end{array}$
11	1	$\begin{array}{r}\mathrm{\$}10(11)+\mathrm{\$}20(1)=\mathrm{\$}130\end{array}$
10	2	$\begin{array}{r}\mathrm{\$}10(10)+\mathrm{\$}20(2)=\mathrm{\$}140\end{array}$
9	3	$\begin{array}{r}\mathrm{\$}10(9)+\mathrm{\$}20(3)=\mathrm{\$}150\end{array}$
8	4	$\begin{array}{r}\mathrm{\$}10(8)+\mathrm{\$}20(4)=\mathrm{\$}160\end{array}$
7	5	$\begin{array}{r}\mathrm{\$}10(7)+\mathrm{\$}20(5)=\mathrm{\$}170\end{array}$
6	6	$\begin{array}{r}\mathrm{\$}10(6)+\mathrm{\$}20(6)=\mathrm{\$}180\end{array}$
5	7	$\begin{array}{r}\mathrm{\$}10(5)+\mathrm{\$}20(7)=\mathrm{\$}190\end{array}$
4	8	$\begin{array}{r}\mathrm{\$}10(4)+\mathrm{\$}20(8)=\mathrm{\$}200\end{array}$
3	9	$\begin{array}{r}\mathrm{\$}10(3)+\mathrm{\$}20(9)=\mathrm{\$}210\end{array}$
2	10	$\begin{array}{r}\mathrm{\$}10(2)+\mathrm{\$}20(10)=\mathrm{\$}220\end{array}$
1	11	$\begin{array}{r}\mathrm{\$}10(1)+\mathrm{\$}20(11)=\mathrm{\$}230\end{array}$
0	12	$\begin{array}{r}\mathrm{\$}10(0)+\mathrm{\$}20(12)=\mathrm{\$}240\end{array}$

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In the table we listed all the possible ways you can get twelve $10 bills and $20 bills and the total amount of money for each possibility. The correct amount is given when Andrew has six $10 bills and six $20 bills.
::在表格中,我们列出了所有可能的方式,你可以拿到12张10元的钞票和20张20元的钞票,以及每个可能的货币总额。当安德鲁有6张10元的钞票和6张20元的钞票时,可以给出正确的金额。

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Answer: Andrew gets six $10 bills and six $20 bills.
::回答:安德鲁得到6张10美元和6张20美元。

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Check
::支票支票支票支票

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Six $10 bills and six $20 bills $\begin{array}{r}\to 6(\mathrm{\$}10)+6(\mathrm{\$}20)=\mathrm{\$}60+\mathrm{\$}120=\mathrm{\$}180\end{array}$
::六张10美元的账单和六张20美元的账单 6 6(10美元)+6(20美元)=60+120美元=180美元

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The answer checks out.
::答案检查出来。

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Let’s solve the same problem using the method “Look for a Pattern .”
::让我们用“寻找模式”的方法来解决同样的问题。

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Method 2: Looking for a Pattern
::方法2:寻找模式

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Understand
::理解

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Andrew gives the bank teller a $180 check.
::安德鲁给银行出纳员180美元的支票

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The bank teller gives Andrew 12 bills. These bills are a mix of $10 bills and $20 bills.
::银行出纳给安德鲁12张帐单 这些帐单包括10张帐单和20张帐单

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We want to know how many of each kind of bill Andrew receives.
::我们想知道 安德鲁收到多少帐单

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Strategy
::战略战略战略战略 战略战略战略 战略

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Let’s start by making a table just as we did above. However, this time we will look for patterns in the table that can be used to find the solution.
::让我们首先像前面一样做一张桌子。 但是,这次我们将在桌子上寻找可以用来找到解决办法的模式。

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Apply strategy/solve
::应用战略/解决方案

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Let’s fill in the rows of the table until we see a pattern.
::让我们填满表格的行,直到我们看到一个模式。

$10 bills	$20 bills	Total amount
12	0	$\begin{array}{r}\mathrm{\$}10(12)+\mathrm{\$}20(0)=\mathrm{\$}120\end{array}$
11	1	$\begin{array}{r}\mathrm{\$}10(11)+\mathrm{\$}20(1)=\mathrm{\$}130\end{array}$
10	2	$\begin{array}{r}\mathrm{\$}10(10)+\mathrm{\$}20(2)=\mathrm{\$}140\end{array}$

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We see that every time we reduce the number of $10 bills by one and increase the number of $20 bills by one, the total amount increases by $10. The last entry in the table gives a total amount of $140, so we have $40 to go until we reach our goal. This means that we should reduce the number of $10 bills by four and increase the number of $20 bills by four. That would give us six $10 bills and six $20 bills.
::我们看到,每次我们减少10张帐单,减少1张,增加1张20张帐单,总金额就增加10美元。 表中最后一个条目的总额是140美元,因此我们只有40美元,直到达到我们的目标。这意味着我们应该减少10张帐单,减少4张,将20张帐单增加4张。 这将给我们6张10美元,增加6张20美元。

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Answer: Andrew gets six $10 bills and six $20 bills.
::回答:安德鲁得到6张10美元和6张20美元。

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Check
::支票支票支票支票

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Six $10 bills and six $20 bills $\begin{array}{r}\to 6(\mathrm{\$}10)+6(\mathrm{\$}20)=\mathrm{\$}60+120=\mathrm{\$}180\end{array}$
::六张10美元的账单和六张20美元的账单 6 6(10美元)+6(20美元)=60+120=180美元

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The answer checks out.
::答案检查出来。

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You can see that the second method we used for solving the problem was less tedious. In the first method, we listed all the possible options and found the answer we were seeking. In the second method, we started by listing the options, but we found a pattern that helped us find the solution faster. The methods of “Making a Table” and “Looking for a Pattern” are both more powerful if used alongside other problem-solving methods.
::你可以看到,我们用来解决问题的第二种方法并不那么乏味。在第一种方法中,我们列出了所有可能的选项并找到了我们所寻求的答案。在第二种方法中,我们首先列出了选项,但我们发现了一个帮助我们更快地找到解决方案的模式。 如果与其他解决问题的方法同时使用,“制表”和“寻找模式”的方法都更为强大。

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Solving Real-World Problems Using Selected Strategies as Part of a Plan
::利用选定战略作为计划的一部分解决现实世界问题

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Anne is making a box without a lid. She starts with a 20 in. square piece of cardboard and cuts out four equal squares from each corner of the cardboard as shown. She then folds the sides of the box and glues the edges together. How big does she need to cut the corner squares in order to make the box with the biggest volume ?
::Anne正在做一个没有盖子的盒子。 她从一张20英寸的纸板开始, 从纸板的每个角落切开四个相等的方形。 然后她折叠盒子的两边, 然后把边缘粘在一起。 她需要多大才能切开角落的方形, 才能使盒子的体积最大?

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Solution
::解决方案

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Step 1:
::第1步:

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Understand
::理解

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Anne makes a box out of a $\begin{array}{r}20in\times 20in\end{array}$ piece of cardboard.
::安妮用纸板 做一个20英寸20的盒子

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She cuts out four equal squares from the corners of the cardboard.
::她从纸板的角落切开四个等式方块

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She folds the sides and glues them to make a box.
::她把两边折叠起来 粘合起来做个盒子

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How big should the cut out squares be to make the box with the biggest volume?
::用最大体积的盒子 做成方形板应该有多大?

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Step 2:
::第2步:

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Strategy
::战略战略战略战略 战略战略战略 战略

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We need to remember the formula for the volume of a box.
::我们需要记住一个盒子体积的公式

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$\begin{array}{r}\text{Volume}=\text{Area of base}\times \text{height}\end{array}$
::体积=基数x58的区域

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$\begin{array}{r}\text{Volume}=\text{width}\times \text{length}\times \text{height}\end{array}$
::音量=widthxx长xxh8

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Make a table of values by picking different values for the side of the squares that we are cutting out and calculate the volume.
::绘制一个数值表,为我们正在切开的方形的侧面选择不同的数值,并计算其体积。

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Step 3:
::第3步:

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Apply strategy/solve
::应用战略/解决方案

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Let’s “make” a box by cutting out four corner squares with sides equal to 1 inch. The diagram will look like this:
::让我们“做”一个盒子,切除四个角方形,方形等于1英寸。 图表将像这样看:

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You see that when we fold the sides over to make the box, the height becomes 1 inch, the width becomes 18 inches and the length becomes 18 inches.
::你看,当我们折叠侧面来做盒子时, 高度变成1英寸, 宽度变成18英寸, 长度变成18英寸。

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$\begin{array}{r}\text{Volume}=\text{width}\times \text{length}\times \text{height}\end{array}$
::音量=widthxx长xxh8

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$\begin{array}{r}\text{Volume}=18\times 18\times 1=324i{n}^3\end{array}$
::音量=18x18x18x1=324英寸3

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Let’s make a table that shows the value of the box for different square sizes:
::让我们制作一个表格,显示不同平方大小的框值:

Side of Square	Box Height	Box Width	Box Length	Volume
1	1	18	18	$\begin{array}{r}18\times 18\times 1=324\end{array}$
2	2	16	16	$\begin{array}{r}16\times 16\times 2=512\end{array}$
3	3	14	14	$\begin{array}{r}14\times 14\times 3=588\end{array}$
4	4	12	12	$\begin{array}{r}12\times 12\times 4=576\end{array}$
5	5	10	10	$\begin{array}{r}10\times 10\times 5=500\end{array}$
6	6	8	8	$\begin{array}{r}8\times 8\times 6=384\end{array}$
7	7	6	6	$\begin{array}{r}6\times 6\times 7=252\end{array}$
8	8	4	4	$\begin{array}{r}4\times 4\times 8=128\end{array}$
9	9	2	2	$\begin{array}{r}2\times 2\times 9=36\end{array}$
10	10	0	0	$\begin{array}{r}0\times 0\times 10=0\end{array}$

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We stop at a square of 10 inches because at this point we have cut out all of the cardboard and we can’t make a box any more. From the table we see that we can make the biggest box if we cut out squares with a side length of three inches. This gives us a volume of $\begin{array}{r}588i{n}^3\end{array}$ .
::我们停在10英寸的平方,因为此时我们切掉了所有的纸板,再也不能做一个盒子了。 从桌子上可以看到,如果我们用3英寸的侧长切开方块,我们就能做最大的方块。 这样一来,我们就可以做588英寸的体积。

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Answer The box of greatest volume is made if we cut out squares with a side length of three inches.
::如果我们切开边长三英寸的方形方形 就会做出数量最大的回答

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Step 4:
::第4步:

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Check
::支票支票支票支票

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We see that $\begin{array}{r}588i{n}^3\end{array}$ is the largest volume appearing in the table. We picked integer values for the sides of the squares that we are cut out. Is it possible to get a larger value for the volume if we pick non-integer values? Since we get the largest volume for the side length equal to three inches, let’s make another table with values close to three inches that is split into smaller increments:
::我们看到588英寸3是表中最大的数量。 我们选择了我们被切除的方形两侧的整数值。 如果我们选择非整数值, 是否能得到更大的量值 ? 既然我们得到了最大量的副长度等于三英寸, 那么让我们再做一张接近三英寸的表, 将其分成较小的递增数 :

Side of Square	Box Height	Box Width	Box Length	Volume
2.5	2.5	15	15	$\begin{array}{r}15\times 15\times 2.5=562.5\end{array}$
2.6	2.6	14.8	14.8	$\begin{array}{r}14.8\times 14.8\times 2.6=569.5\end{array}$
2.7	2.7	14.6	14.6	$\begin{array}{r}14.6\times 14.6\times 2.7=575.5\end{array}$
2.8	2.8	14.4	14.4	$\begin{array}{r}14.4\times 14.4\times 2.8=580.6\end{array}$
2.9	2.9	14.2	14.2	$\begin{array}{r}14.2\times 14.2\times 2.9=584.8\end{array}$
3	3	14	14	$\begin{array}{r}14\times 14\times 3=588\end{array}$
3.1	3.1	13.8	13.8	$\begin{array}{r}13.8\times 13.8\times 3.1=590.4\end{array}$
3.2	3.2	13.6	13.6	$\begin{array}{r}13.6\times 13.6\times 3.2=591.9\end{array}$
3.3	3.3	13.4	13.4	$\begin{array}{r}13.4\times 13.4\times 3.3=592.5\end{array}$
3.4	3.4	13.2	13.2	$\begin{array}{r}13.2\times 13.2\times 3.4=592.4\end{array}$
3.5	3.5	13	13	$\begin{array}{r}13\times 13\times 3.5=591.5\end{array}$

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Notice that the largest volume is not when the side of the square is three inches, but rather when the side of the square is 3.3 inches.
::注意最大体积不是当方形的侧面为3英寸时,而是当方形的侧面为3.3英寸时。

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Our original answer was not incorrect, but it was not as accurate as it could be. We can get an even more accurate answer if we take even smaller increments of the side length of the square. To do that, we would choose smaller measurements that are in the neighborhood of 3.3 inches.
::我们最初的答案并不不正确,但并不尽如人意。 如果我们对方形侧长进行更小的递增,我们可以得到更准确的答案。 为了做到这一点,我们将选择在3.3英寸附近进行更小的测量。

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Meanwhile, our first answer checks out if we want it rounded to zero decimal places, but a more accurate answer is 3.3 inches.
::同时,如果我们想要它四舍五入到小数点后零位, 我们的第一个答案就会被检查出来, 但更准确的答案是3.3英寸。

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Example
::示例示例示例示例

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Example 1
::例1

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Tickets to an event go on sale for $20 six weeks before the event, and go up in price by $5 each week. What is the price of tickets one week before the event?
::活动前六个星期售出20美元的入场券,每星期涨价5美元。 活动前一周的入场券价格是多少?

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We want to know the price one week before the event. We know the price six weeks before the event is $20, and that it goes up $5 each week.
::我们想知道前一周的价格。我们知道前六个星期的价格是20美元,每星期涨5美元。

Weeks before event.	Price of tickets.
6	$\begin{array}{r}\mathrm{\$}20\end{array}$
5	$\begin{array}{r}\mathrm{\$}20+\mathrm{\$}5=\mathrm{\$}25\end{array}$
4	$\begin{array}{r}\mathrm{\$}25+\mathrm{\$}5=\mathrm{\$}30\end{array}$
3	$\begin{array}{r}\mathrm{\$}30+\mathrm{\$}5=\mathrm{\$}35\end{array}$
2	$\begin{array}{r}\mathrm{\$}35+\mathrm{\$}5=\mathrm{\$}40\end{array}$
1	$\begin{array}{r}\mathrm{\$}40+\mathrm{\$}5=\mathrm{\$}45\end{array}$

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One week before the event, the tickets will cost $45.
::事发前一周 票价为45美元

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Review 
::回顾

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1. Britt has $2.25 in nickels and dimes. If she has 40 coins in total, how many of each coin does she have?
   ::Britt有2.25美元硬币和硬币,如果她共有40个硬币,那么她每个硬币有多少?
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2. Jeremy divides a 160-square-foot garden into plots that are either 10 or 12 square feet each. If there are 14 plots in all, how many plots are there of each size?
   ::Jeremy将160平方英尺的花园分成10或12平方英尺的地块。 如果共有14块地,那么每个大小有多少块地?
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3. A pattern of squares is put together as shown. How many squares are in the $\begin{array}{r}{12}^{th}\end{array}$ diagram? $\begin{array}{r}\end{array}$
   ::方形的图案按所示组合。第12张图中有多少方形?
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4. In Harrisville, local housing laws specify how many people can live in a house or apartment: the maximum number of people allowed is twice the number of bedrooms, plus one. If Jan, Pat, and their four children want to rent a house, how many bedrooms must it have?
   ::在Harrisville,当地住房法规定有多少人可以住在家里或公寓:最多允许的人数是卧室数的两倍,加上一个。 如果Jan、Pat和他们的四个孩子想租房,那么它必须有多少卧室?
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5. A restaurant hosts children’s birthday parties for a cost of $120 for the first six children (including the birthday child) and $30 for each additional child. If Jaden’s parents have a budget of $200 to spend on his birthday party, how many guests can Jaden invite?
   ::一家餐馆招待儿童生日晚会,头六个孩子(包括生日孩子)费用120美元,每个孩子30美元。 如果Jaden的父母有200美元的预算用于生日晚会,那么Jaden可以邀请多少客人?
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6. A movie theater with 200 seats charges $8 general admission and $5 for students. If the 5:00 showing is sold out and the theater took in $1468 for that showing, how many of the seats are occupied by students?
   ::如果5: 00的演出被卖光了,剧院收了1468美元的演出,有多少座位被学生占据?
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7. Oswald is trying to cut down on drinking coffee. His goal is to cut down to 6 cups per week. If he starts with 24 cups the first week, then cuts down to 21 cups the second week and 18 cups the third week, how many weeks will it take him to reach his goal?
   ::Oswald试图削减咖啡。他的目标是每周削减到6杯。 如果他从第一周的24杯开始,那么第二周将削减到21杯,第三周将削减到18杯,他达到目标需要多少周时间?
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8. Taylor checked out a book from the library and it is now 5 days late. The late fee is 10 cents per day. How much is the fine?
   ::Taylor在图书馆查了一本书 现在晚了5天 迟费是每天10美分 罚款是多少?
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9. Mikhail is filling a sack with oranges.
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   1. If each orange weighs 5 ounces and the sack will hold 2 pounds, how many oranges will the sack hold before it bursts?
      ::如果每只橙子重5盎司 麻袋会保持2磅 麻袋在爆炸前会保持多少橙子?
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   2. Mikhail plans to use these oranges to make breakfast smoothies. If each smoothie requires $\begin{array}{r}\frac{3}{4}\end{array}$ cup of orange juice, and each orange will yield half a cup, how many smoothies can he make?
      ::米哈伊尔计划用这些橙子做早餐冰淇淋。如果每杯冰淇淋需要34杯橙汁,每杯橙汁将产生半杯,他能做多少冰淇淋?
   
   ::米哈依(Mikhail)正用橘子填满一袋。如果每只橙子重5盎司,麻袋将保持2磅,麻袋在爆炸前将保持多少橙子?米哈依计划用这些橙子做早餐冰淇淋。如果每杯冰淇淋需要34杯橙汁,每杯橙汁将产生半杯,他能做多少冰淇淋?
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10. Jessamyn takes out a $150 loan from an agency that charges 12% of the original loan amount in interest each week. If she takes five weeks to pay off the loan, what is the total amount (loan plus interest) she will need to pay back?
    ::Jessamyn从一个机构那里借出150美元的贷款,该机构每周收取原贷款金额的12%的利息。 如果她用五个星期来偿还贷款,她需要偿还的总额(贷款加利息)是多少?
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11. How many hours will a car traveling at 75 miles per hour take to catch up to a car traveling at 55 miles per hour if the slower car starts two hours before the faster car?
    ::一辆每小时75英里行驶的汽车要追上一辆每小时55英里行驶的汽车,如果较慢的汽车在较快的汽车前两小时开动,需要多少小时才能赶上一辆每小时55英里行驶的汽车?
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12. Grace starts biking at 12 miles per hour. One hour later, Dan starts biking at 15 miles per hour, following the same route. How long will it take him to catch up with Grace?
    ::格蕾丝开始骑自行车,每小时12英里。一小时后,丹开始骑自行车,每小时15英里,沿同一路线。他要多久才能赶上格蕾丝?
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13. A new theme park opens in Milford. On opening day, the park has 120 visitors; on each of the next three days, the park has 10 more visitors than the day before; and on each of the three days after that, the park has 20 more visitors than the day before.
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    1. How many visitors does the park have on the seventh day?
       ::公园第七天有多少访客?
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    2. How many total visitors does the park have all week?
       ::整个礼拜公园有多少访客?
    
    ::在密尔福德,一个新的主题公园开放。 在开幕日,公园有120名访客;在接下来的三天中,每个公园的访客比前一天多10人;在三天后,每个公园的访客比前一天多20人。第七天公园有多少访客?整个星期公园的访客总数是多少?
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14. Lemuel wants to enclose a rectangular plot of land with a fence. He has 24 feet of fencing. What is the largest possible area that he could enclose with the fence?
    ::莱缪尔想用栅栏围住一块长方形土地,他有24英尺长的栅栏。
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15. Quizzes in Keiko’s history class are worth 20 points each. Keiko scored 15 and 18 points on her last two quizzes. What score does she need on her third quiz to get an average score of 17 on all three?
    ::Keiko历史课的Quizzes各值20分。 Keiko在最后两次测验中得15分和18分。 在第三次测验中,她需要多少分才能在所有三次测验中平均得17分?
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16. Mark is three years older than Janet, and the sum of their ages is 15. How old are Mark and Janet?
    ::马克比珍妮特大三岁 他们的年龄总和是15岁 马克和珍妮特几岁?
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17. In a one-on-one basketball game, Jane scored $\begin{array}{r}1\frac{1}{2}\end{array}$ times as many points as Russell. If the two of them together scored 10 points, how many points did Jane score?
    ::在一对一的篮球比赛中,Jane得分是Russell的112倍。如果两者加在一起得10分,Jane得分是多少?
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18. Scientists are tracking two pods of whales during their migratory season. On the first day of June, one pod is 120 miles north of a certain group of islands, and every day thereafter it gets 15 miles closer to the islands. The second pod starts out 160 miles east of the islands on June 3, and heads toward the islands at a rate of 20 miles a day.
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    1. Which pod will arrive at the islands first, and on what day?
       ::哪个舱位会先到达群岛 什么时候到达?
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    2. How long after that will it take the other pod to reach the islands?
       ::再过多久,另一个舱才能到达岛上?
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    3. Suppose the pod that reaches the islands first immediately heads south from the islands at a rate of 15 miles a day, and the pod that gets there second also heads south from there at a rate of 25 miles a day. On what day will the second pod catch up with the first?
       ::假设首先到达群岛的舱位会以每天15英里的速度立即从群岛向南飞去,而到达群岛的舱位也会以每天25英里的速度向南飞去。 第二个舱位会在哪一天赶上第一个舱位?
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    4. How far will both pods be from the islands on that day?
       ::那天两个舱都离群岛多远?
    
    ::科学家们在迁徙季节追踪了两个鲸群。 6月的第一天,一个鲸群位于某个岛屿群以北120英里处,每天离岛屿更近15英里。 第二个鲸群于6月3日从岛屿以东160英里处出发,每天向岛屿以20英里的速度前进。 哪个鲸群将首先到达岛屿,然后是哪一天? 之后,另一个鲸群将走多久才能到达岛屿? 假设第一个到达岛屿的鲸群每天以15英里的速度从岛屿向南直接到达岛屿,然后每天从那里以25英里的速度向南到达第二个鲸群。 第二只鲸群将在哪一天赶到第一个岛? 在那一天,两个鲸群将离岛屿多远?

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Review (Answers)
::回顾(答复)

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Click to see the answer key or go to the Table of Contents and click on the Answer Key under the 'Other Versions' option.
::单击可查看答题键, 或转到目录中, 单击“ 其他版本” 选项下的答题键 。

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Texas Instruments Resources
::得克萨斯州工具资源

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In the CK-12 Texas Instruments Algebra I FlexBook® resource, there are graphing calculator activities designed to supplement the objectives for some of the lessons in this chapter. See .
::在CK-12得克萨斯州仪器代数I FlexBook资源中,有图表计算活动,旨在补充本章某些经验教训的目标。