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# 用 Python 讲授求数字根
> 原文:<https://www.blog.pythonlibrary.org/2013/07/16/using-python-to-teach-about-finding-the-digital-root/>
我妻子教三年级的数学,她最近了解了获得数字的数字根的过程。数字根是一个单个数字,它是通过对各个数字求和得到的。因此,对于 15你将 1+5 相加得到 6。因此 6 是 15 的数字根。与我妻子一起工作的培训师解释说,你可以使用数字根来检查你的答案,这将给孩子们另一种方法来确定他们的答案是否正确。这里有一个例子:
```py
15 1 + 5 = 6
+12 1 + 2 = 3
6 + 3 = 9
----
27 2 + 7 = 9
```
这里我们有两个操作数:15 和 12。如果你把这些加在一起你得到 27。要用数字根来检查你的答案你要把两个操作数中的数字相加如上所述。所以 15 变成了 1+5 或 612 变成了 1+2 或 3。然后你把这两个根加在一起得到 9。然后你通过把它的数字相加来检查你的答案在这种情况下是 2+7 等于 9。减法、乘法和除法的规则略有不同。我们将学习加法、减法和乘法。我们跳过除法因为我还没有找到一个很好的解释它是如何工作的我不想仅仅使用我无法解释的公式。
此时,您可能想知道 Python 从何而来。我们将使用 wxPython 创建一个简单的 GUI让我们看看这是如何工作的。开始编码吧
### 创建用于查找数字根的 GUI
[![digiroot](img/b22ca4c0dd76a7fef8f65a43ed7c1b8d.png)](https://www.blog.pythonlibrary.org/wp-content/uploads/2013/07/digiroot.png)
创建 GUI 一开始有点棘手,但随着您了解数字根是如何工作的,很快就变得容易了。您唯一需要遵循的包是 wxPython您可以在这里获得[。一旦你安装好了,你就可以开始了。现在让我们看一下代码:](http://wxpython.org/)
```py
import wx
########################################################################
class DigiPanel(wx.Panel):
""""""
#----------------------------------------------------------------------
def __init__(self, parent):
"""Constructor"""
wx.Panel.__init__(self, parent)
size = (50, -1)
firstNumLbl = wx.StaticText(self, size=size)
self.firstNum = wx.TextCtrl(self, size=size)
self.digitalRootOne = wx.StaticText(self)
operators = ["+", "-", "x"]
self.operatorsCbo = wx.ComboBox(self, value="+", choices=operators,
size=size)
self.secondNum = wx.TextCtrl(self, size=size)
self.digitalRootTwo = wx.StaticText(self)
self.digiRootLbl = wx.StaticText(self, size=(108, -1))
self.digitalRootAnswer = wx.StaticText(self)
totalLbl = wx.StaticText(self, size=size, label="Answer:")
self.total = wx.TextCtrl(self, size=size, style=wx.TE_READONLY)
self.totalRoot = wx.StaticText(self)
calcBtn = wx.Button(self, label="Calculate")
calcBtn.Bind(wx.EVT_BUTTON, self.onCalculate)
digiRootBtn = wx.Button(self, label="Find Digital Root")
digiRootBtn.Bind(wx.EVT_BUTTON, self.onDigitalRoot)
# layout the widgets
mainSizer= wx.BoxSizer(wx.VERTICAL)
firstSizer = wx.BoxSizer(wx.HORIZONTAL)
secondSizer = wx.BoxSizer(wx.HORIZONTAL)
totalSizer = wx.BoxSizer(wx.HORIZONTAL)
digiAnswerSizer = wx.BoxSizer(wx.HORIZONTAL)
btnSizer = wx.BoxSizer(wx.HORIZONTAL)
firstSizer.Add(firstNumLbl, 0, wx.ALL, 5)
firstSizer.Add(self.firstNum, 0, wx.ALL, 5)
firstSizer.Add(self.digitalRootOne, 0, wx.ALL, 5)
mainSizer.Add(firstSizer, 0, wx.ALL, 5)
secondSizer.Add(self.operatorsCbo, 0, wx.ALL, 5)
secondSizer.Add(self.secondNum, 0, wx.ALL, 5)
secondSizer.Add(self.digitalRootTwo, 0, wx.ALL, 5)
mainSizer.Add(secondSizer, 0, wx.ALL, 5)
digiAnswerSizer.Add(self.digiRootLbl, 0, wx.ALL, 5)
digiAnswerSizer.Add(self.digitalRootAnswer, 0, wx.ALL, 5)
mainSizer.Add(digiAnswerSizer, 0, wx.ALL, 5)
totalSizer.Add(totalLbl, 0 ,wx.ALL, 5)
totalSizer.Add(self.total, 0, wx.ALL, 5)
totalSizer.Add(self.totalRoot, 0, wx.ALL, 5)
mainSizer.Add(totalSizer, 0, wx.ALL, 5)
btnSizer.Add(calcBtn, 0, wx.ALL|wx.CENTER, 5)
btnSizer.Add(digiRootBtn, 0, wx.ALL|wx.CENTER, 5)
mainSizer.Add(btnSizer, 0, wx.ALL|wx.CENTER, 5)
self.SetSizer(mainSizer)
#----------------------------------------------------------------------
def getAddString(self, number):
"""
Calculate the digital string
"""
if "-" in str(number):
answer = number
strNumbers = [str(number)]
else:
strNumbers = [i for i in str(number)]
answer = sum(map(int, strNumbers))
newAnswer = None
root = " + ".join(strNumbers) + " = " + str(answer)
while answer >= 10:
strNumbers = [i for i in str(answer)]
answer = sum(map(int, strNumbers))
newRoot = " + ".join(strNumbers) + " = " + str(answer)
root += " => " + newRoot
return root, answer
#----------------------------------------------------------------------
def getMultiString(self, number, number2):
"""
Get the string associated with multiplication
"""
answer = number * number2
root = "%s x %s = %s" % (number, number2, answer)
newAnswer = 1
if answer >= 10:
root += " => " + self.getAddString(answer)[0]
return root
#----------------------------------------------------------------------
def getSubtractionString(self, number, number2, total=None):
"""
Get subtraction string
"""
if not total:
answer = number - number2
root = "%s - %s = %s" % (number, number2, answer)
else:
root = "%s" % total
answer = total
if answer < 0:
# then we need to add 9
newAns = answer + 9
root += " => %s + 9 = %s" % (answer, newAns)
return root
#----------------------------------------------------------------------
def onCalculate(self, event):
"""
Calculate the total
"""
firstNum = int( self.firstNum.GetValue() )
secondNum = int( self.secondNum.GetValue() )
operator = self.operatorsCbo.GetValue()
if operator == "+":
total = firstNum + secondNum
elif operator == "x":
total = firstNum * secondNum
elif operator == "-":
total = firstNum - secondNum
self.total.SetValue(str(total))
#----------------------------------------------------------------------
def onDigitalRoot(self, event):
"""
Show digital root
"""
firstNum = int( self.firstNum.GetValue() )
secondNum = int( self.secondNum.GetValue() )
total = int(self.total.GetValue())
operator = self.operatorsCbo.GetValue()
firstRoot, firstAnswer = self.getAddString(firstNum)
secondRoot, secondAnswer = self.getAddString(secondNum)
if operator == "+":
totalRoot, _ = self.getAddString(total)
rootTotal = sum([firstAnswer, secondAnswer])
ans = "%s + %s = %s" % (firstAnswer, secondAnswer, rootTotal)
if rootTotal >= 10:
root, _ = self.getAddString(rootTotal)
ansRoot += " => " + root
else:
ansRoot = ans
self.digiRootLbl.SetLabel("A + B = root")
elif operator == "x":
ansRoot = self.getMultiString(firstAnswer, secondAnswer)
totalRoot, _ = self.getAddString(total)
self.digiRootLbl.SetLabel("A x B = root")
elif operator == "-":
ansRoot = self.getSubtractionString(firstAnswer, secondAnswer)
totalRoot = self.getSubtractionString("", "", total)
self.digiRootLbl.SetLabel("A - B = root")
self.digitalRootOne.SetLabel("A: " + firstRoot)
self.digitalRootTwo.SetLabel("B: " + secondRoot)
self.digitalRootAnswer.SetLabel(ansRoot)
self.totalRoot.SetLabel(totalRoot)
########################################################################
class DigiFrame(wx.Frame):
""""""
#----------------------------------------------------------------------
def __init__(self):
"""Constructor"""
title = "Digital Root Finder"
size = (800, 600)
wx.Frame.__init__(self, None, title=title, size=size)
panel = DigiPanel(self)
self.Show()
#----------------------------------------------------------------------
def main():
"""
Run the program
"""
app = wx.App(False)
frame = DigiFrame()
app.MainLoop()
if __name__ == "__main__":
main()
```
在这里,我们按行创建了一组小部件。你可以用 wx。GridBagSizer 或类似的东西,而不是嵌套的 box sizer但是我更喜欢使用 box sizer 的灵活性,即使它变得有点复杂。总之,我们布局了四行窗口小部件和一行较小的按钮。一些静态文本小部件充当间隔符来帮助对齐项目。我们有两个按钮:一个用于计算答案一个用于寻找数字根。calculate 按钮检查组合框,找出应该执行的操作,然后采取相应的行动。另一个按钮的事件处理程序 **onDigitalRoot** 要复杂得多。
我们再次检查选择了哪个运算符(+、-或 x),然后我们算出数字根。对于加法,我们实际上最终调用了 **getAddString** 来检查数字是否为负。如果是,我们不加数字。是的,如果我们得到一个大于-9 的值,这可能是一个问题,但是如果发生这种情况,那么我们就做错了别的事情。无论如何,如果它高于 9那么我们需要总结小部件这就是下面几行为我们做的:
```py
strNumbers = [i for i in str(number)]
answer = sum(map(int, strNumbers))
```
然后我们使用一个 while 循环来不断累加答案的数字,以防我们得到一个非常大的操作数。因为这主要是针对小学生的,这有点过分了,但是我知道有人会问为什么我们不检查。减法非常相似。最大的区别是,如果数字根答案小于零,你就要加九。这是补数(即使其完整所需的数量)。我真的没有找到一个更深入的答案来解释你为什么这么做。不管怎样,要得到减法数字根,你需要得到操作数的根,然后将它们相减。
举个例子:假设你有 15 - 12 = 3。15 变成 1+5 或 612 变成 1+2 或 3。所以现在你取 6-3 = 3和 15-12 一样。
乘法也很简单。我们快速做个例子:12 x 10 = 120。12 变成 1+2 或 310 变成 1+0 或 1。因为这是乘法所以你用 3x1 得到 3。答案是 120但它的数字根是 1+2+0 或 3。
### 包扎
现在你知道如何在四则运算中找到数字根。您还了解了如何创建一个简单的 GUI 来显示它是如何完成的。数学和巨蟒摇滚!
### 附加阅读
* [数字根 PDF](http://www.teachingideas.co.uk/maths/files/digitalroots.pdf) 来自教学思路
* 维基百科关于[数字根的文章](http://en.wikipedia.org/wiki/Digital_root)
* 维基百科关于[的文章补充了](http://en.wikipedia.org/wiki/Complement)
* [数字根解释](http://www.thonky.com/nine-hours-nine-persons-nine-doors/digital-root/)
### 下载源代码
* [digiroot.zip](https://www.blog.pythonlibrary.org/wp-content/uploads/2013/07/digiroot.zip)