1.3 确定表格中的比例关系-interactive
章节大纲
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Coffee House Spending
::咖啡厅开支Your math teacher has a serious coffee habit. Every morning she goes to her favorite coffee house and buys a latte for $3.75. Here is a table to represent how much money she spends in a week:
::你的数学老师有一个严重的咖啡习惯。每天早上她去她最喜欢的咖啡屋, 买杯拿铁3.75美元。这里是一张表,用来代表她一周花多少钱:Money $3.75 $7.50 Days 1 2 3 4 5 -
Determine the total for days 3, 4 and 5 and create a ratio of money to days.
::确定第3、4和5天的总数,并设定货币与日之比。 -
Use the sliders to adjust the numerator to be the money amounts and the denominator to represent the days.
::使用滑动符将分子调整为货币金额和代表天数的分母。
+Do you want to reset the PLIX?Progress0 / 51.Determine how much money your math teacher spent on lattes on day 3 of the week.
::确定你的数学老师 每周第3天在拿铁上花多少钱a$3.75
b$7.50
c$11.25
d$15.00
The table in this interactive is an example of a proportional relationship . All the ratios you set up were equal. These are also known as equivalent ratios . If your break this down into its key components, you will see that :
::此交互式表格中的表格是比例关系的一个示例。 您设置的所有比率都是相等的。 这些比率也被称为等值比率。 如果您将其细分为关键组成部分, 您将会看到 :-
A
proportion
is an
equation
that sets equivalent ratios equal to each other. All of these rates create a proportion because they are in a proportional relationship.
::比例是一个等式,它规定等同比率对等,所有这些比率都形成一个比例,因为它们是比例关系。 -
$3.75 is the
rate of change
. It describes how fast the output (the total cost) increases each day.
::3.75美元是变化率,说明产出(总成本)每天增长的速度。 -
The rate of change is always
constant
(or same) for any proportional relationship.
::任何比例关系的变化率总是不变(或相同)。
Painting the House
::画房子Max is painting his house. He needs to cover 3,200 square feet of wall space. Based on the table below, how many gallons of paint does Max need to buy?
::他需要覆盖3200平方英尺的墙壁空间。根据下面的表格, Max需要买多少加仑的油漆?gallons 1 2 3 4 5 square feet 400 800 1,200 1,600 2,000 Use the sliders to change the proportions and determine how many gallons of paint are needed.
::使用滑块来改变比例,并确定需要多少加仑油漆。+Do you want to reset the PLIX?The rate of change of a proportional relationship is also called the constant of proportionality because for every rate , the proportion of is constant. This constant of proportionality is commonly labeled T he independent value, usually labeled x, is often in the first column of a table. The dependent value, which is usually labeled y, is commonly the second column of a table. Therefore , you can say:
::比例关系的变化率也称为相称性不变值,因为对于每一比率,依赖性价值的比重是不变的。这一相称性不变值通常被贴上标签 k。独立值通常被贴上标签 x,通常在表格第一列中。依赖性值通常被贴上标签 y,通常是表格第二列。因此,你可以说:
::独立值=yx=k
Is it Proportional?
::是相称的吗?Determine if the following tables represent proportional relationships. If so, find the constant of proportionality and the equation.
::确定下列表格是否代表比例关系。如果是,请找到相称性和等式的常数。+Do you want to reset the PLIX?Summary
::摘要-
Tables can be used to determine whether or not data is proportional.
::可用表格确定数据是否成比例。 -
Proportional relationships have a constant rate of change or constant of proportionality, called
::比例关系有不变的变化率或相称性不变,称为k。 -
You can use
to find other values within the proportional relationship.
::您可以使用 k 在比例关系中找到其它值 。
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Determine the total for days 3, 4 and 5 and create a ratio of money to days.