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  • 以十进制除法的十进制

    Practice Dividing Decimals by Decimals
    ::以十进制区分十进制

     

     

     

    How much horsepower do toy cars have?
    ::玩具车有多少马力?

    lesson content
    RC Car

    You can use horsepower to measure the power of a car engine. A regular family car has about 100 horsepower. High performance cars have between 300 to 450 horsepower. Race cars have 750 horsepower or higher.
    ::您可以使用马力测量汽车发动机的功率。普通家庭汽车拥有约100匹马力。高性能汽车拥有300至450匹马力,赛马汽车拥有750匹或以上的马力。

    With the interactive below, you will  find the amount of work done by each toy car driving up a ramp as measured in Joules. You will divide the time it takes to drive up the ramp to find the power of each car as measured in Watts. You can divide the number of Watts by 746 to find the horsepower of each car.
    ::在下面的交互下方, 您将会发现每辆玩具车驾驶在Joules 测量的斜坡上所完成的工程量。 您将会把开在斜坡上的时间分开, 以找到在Watts 测量的每辆汽车的功率。 您可以将瓦特数除以746, 以找到每辆汽车的马力 。

    To  learn more about power and Watts,  take a look at  this .
    ::了解更多关于电力和瓦茨, 看看这个。

    Find the remote control car with the most horsepower in the interactive below.
    ::找到遥控车 在下面互动的马力最高的地方

     

    INTERACTIVE
    Powerful Toy Cars
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    • Move the decimal point to the correct position to correctly complete the division.
      ::将小数点移到正确位置,以正确完成分割。
    • Press the "Switch Cars" button to change toy cars.
      ::按“开动车”按钮来更换玩具车。
    • Press the "Switch Speed" button to change the speed of the toy car.
      ::按“切换速度”按钮来改变玩具车的速度。
    • Press the "Go" or "Reset" button when it appears to make the car move or put it at the bottom of the ramp.
      ::按下“ Go” 或“ 重置” 按钮, 当它似乎使汽车移动或放在斜坡底部时按下“ Go” 或“ 重置” 按钮 。
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    CK-12 PLIX Interactive
    ::CK-12 PLIX 交互式互动

    Use this PLIX interactive to explore the connection between the placement of the decimal in  a division problem and the quotient . The last question in the PLIX  is about dividing with a decimal in the divisor .
    ::使用此 PLIX 互动来探索小数点在分裂问题中的位置和商数之间的联系。 PLIX 中的最后一个问题是用小数点和小数点来分隔。

     

     

     

    Which gas filled up the mini-bike?
    ::哪一种气体装满了迷你摩托车?

     

    lesson content
    Minibike Racing

    Rachel has a motorized mini-bike with a fuel tank that holds 0.35 gallons. When she goes to refuel her mini-bike, there is usually still some gas left in the tank.  
    ::Rachel有一辆机动小型摩托车,油箱装有0.35加仑的燃料。 当她去加油时,坦克中通常还剩下一些气体。

    She has  three options for different kinds of gas to put in the tank: Regular, Special and Super. Each type of gas costs a different amount.
    ::她可以选择三种不同的气体放入罐体:常规气体、特殊气体和超级气体。每种气体的成本都不同。

    In the interactive below, use the amount of money she paid ($ Sale) and the number of gallons of gas she put in the tank to find out which type of gas she used.
    ::在下文互动中,使用她支付的金额(销售)和她放入油箱的汽油加仑数量,以找出她使用的是哪种气体。

     

    INTERACTIVE
    Gas Prices
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    Figure out which of the three days the gas station had the lowest gas price per gallon.

    ::查一查这三天中哪个加油站的煤气价格是每加仑最低的。

    • Enter the numbers of the sale and and number of gallons into the boxes to set up the division problem.
      ::在框中输入销售数量和加仑数量,以设置分割问题。
    • Enter the numbers to complete the multiplication and subtraction of the division problem.
      ::输入完成分裂问题乘法和减法的编号。
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    Discussion Questions
    ::讨论问题 讨论问题

    1. What steps in division are consistent between dividing with decimals and dividing without decimals?
    ::1. 在除以小数点和除以不以小数点的除以之间,分出哪些步骤一致?

    2. If you plan to round a given number of decimal places in the quotient, how do you know when to stop dividing?
    ::2. 如果打算将一个给定数的小数位位数舍入商数,你怎么知道何时停止分割?

    3. Why do you think gas stations round the rate of $ per gallon to the nearest thousandths place instead of to the nearest cent?
    ::3. 为什么你认为加油站将每加仑1美元的费率按每加仑1美元乘以最近的千位,而不是按最近的百位?

     

     

    C ompare M icroscope Z oom Levels
    ::比较显微镜缩放级别

    lesson content
    Microscope

    Microscopes zoom in to magnify something small and make it easier to see. To show a small object very clearly, microscopes get very close to the object and use stuff that magnifies the image like water, glycerin or oil. The clarity of what you see in a microscope is measured with the Numerical Aperture. Use the interactive to find Numerical Apertures with different zoom levels and different stuff between the lens and the glass. You will use these values to answer questions below.
    ::缩放显微镜, 放大微小的东西, 使其更容易看到。 要非常清楚地显示一个小对象, 显微镜会非常接近对象, 并且使用放大图像的东西, 如水、 甘油或油。 您在显微镜中看到的东西的清晰度是用数字孔径测量的。 使用交互功能来查找不同缩放水平的数值孔径, 以及镜片和玻璃之间不同的物体。 您将使用这些值来回答下面的问题 。

    To learn more about microscopes, you can use this .
    ::要更多了解显微镜, 您可以使用这个 。

     

    INTERACTIVE
    Numerical Aperture of a Microscope
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    Move the red and blue points to see how it affects the numerical aperture of the microscope.
    ::移动红点和蓝色点以观察它如何影响显微镜的数字孔径。

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      Summary
    • Use long division to divide decimals.
      ::使用长除法分隔小数。
    • When dividing two decimals using long division the dividend may not have as many digits as the divisor, so fill in 0s as placeholders between the existing digits of the divisor and the decimal.
      ::当使用长分割除法除以两个小数时,股息的位数可能不及三位数,所以以 0 位数填充现有的三位数和小数数之间的占位符。
    • The number of times the decimal moved in the divisor is the same number of times the decimal moves in the dividend.
      ::在小数点中小数点移动的次数与股息小数点移动的次数相同。