分析：为了减少输入和增加试题内容的随机性，操作数和运算符通过随机函数Rnd产生，操作数的范围是1~10运算符1~4分别代表+、-、*、/。Rnd产生的数是在0~1之间的实数，为产生1~10的整数作为操作数，可通过Int(10*Rnd+1)表达式实现，运算符产生同理。
本例共需要除窗体外的5个控件，其中标签控件1个，文本框1个，命令按钮2个，图形框1个，有关控件设置：
|
默认控件名 |
设置的控件名 |
标题 |
文本 |
图形 |
说明 |
|
Name |
Caption |
Text |
Picture |
||
|
Label1 |
lblExp |
空白 |
无定义 |
无定义 |
显示产生的题目 |
|
Text1 |
txtInput |
无定义 |
空白 |
无定义 |
|
|
Command1 |
cmdOk |
确定 |
无定义 |
无定义 |
每题结束 |
|
Command2 |
cmdMark |
计分 |
无定义 |
无定义 |
最后记分 |
|
Picture1 |
Picture1 |
无定义 |
无定义 |
空白 |
显示题目和结果 |
由于本例有三个事件过程，为了便于事件过程中的数据共享，在事件过程前定义了窗体级变量：
Dim Num1 As Integer, Num2 As Integer ‘存放两个操作数
Dim Sexp As String
Dim Result As Single ‘计算结果
Dim NOk As Integer, NError As Integer ‘统计计算正确与错误
本例通过三个事件过程：
（1） 通过产生随机数生成题目
Private Sub Form_Load()
Dim NOp As Integer, Op As String * 1 ‘存放运算符
Num1 = Int(10 * Rnd + 1) ‘产生1~10之间的操作数
Num2 = Int(10 * Rnd + 1) ‘产生1~10之间的操作数
NOp = Int(4 * Rnd + 1) ‘产生1~4之间的运算符代码
Select Case NOp ‘将1~4之间的运算符代码转换成运算符，并进行四则运算
Case 1
Op = "+": Result = Num1 + Num2
Case 2
Op = "-": Result = Num1 - Num2
Case 3
Op = "*": Result = Num1 * Num2
Case 4
Op = "/": Result = Num1 / Num2
End Select
Sexp = Num1 & Op & Num2 & "="
lblExp = Sexp ‘显示生成题目
End Sub
（2） 在txtInput文本框中输入计算结果，单击“确定”按钮，在图形框显示正确与否
Private Sub cmdOk_Click()
If Val(txtInput) = Result Then ‘输入的结果与计算机计算的结果相同
Picture1.Print Sexp; txtInput; Tab(10); "Y" ‘显示正确符号Y
NOk = NOk + 1 ‘累计计算正确数
Else
Picture1.Print Sexp; txtInput; Tab(10); "X" ‘显示计算错误符号 X
NError = NError + 1 ‘累计计算错误数
End If
txtInput = ""
Form_Load ‘下一个题目生成
End Sub
（3） 计算所得的成绩
Private Sub CmdMark_Click()
Picture1.Print "____________"
Picture1.Print "一共计算" & Int(NOk + NError) & "道题"
Picture1.Print "得分" & Int(NOk / (NOk + NError) * 100)
End Sub
Dim x%, y%, p%
Dim a(0 To 10) As Integer
Dim b(0 To 10) As Integer
Dim s(1 To 10) As Integer
Private Sub Form_Load()
For i = 1 To 10
Label1.Item(i).Caption = ""
Label2.Item(i).Caption = ""
Label3.Item(i).Caption = ""
Label4.Item(i).Caption = ""
Text1.Item(i).Visible = False
Command1.Visible = False
Label5.Item(i).Visible = False
Next
End Sub
Private Sub Command2_Click()
Randomize
For i = 1 To 10
s(i) = Int(4 * Rnd) + 1
x = Int(9 * Rnd) + 1
y = Int(9 * Rnd) + 1
Select Case s(i)
Case 1
a(i) = x
b(i) = y
Label2.Item(i).Caption = "+"
Case 2
x = Int(9 * Rnd) + 1
y = Int(9 * Rnd) + 1
a(i) = x
b(i) = y
If a(i) < b(i) Then
p = a(i)
a(i) = b(i)
b(i) = p
End If
Label2.Item(i).Caption = "-"
Case 3
a(i) = x
b(i) = y
Label2.Item(i).Caption = "*"
Case 4
a(i) = x
b(i) = y
If a(i) < b(i) Then
p = a(i)
a(i) = b(i)
b(i) = p
End If
If a(i) Mod b(i) <> 0 Then
i = i - 1
Else
Label2.Item(i).Caption = "/"
End If
End Select
Label1.Item(i).Caption = a(i)
Label3.Item(i).Caption = b(i)
Label4.Item(i).Caption = "="
Text1.Item(i).Text = ""
Text1.Item(i).Visible = True
Next
Command2.Visible = False
Command1.Visible = True
End Sub
Private Sub Command1_Click()
Dim u%
Dim q(1 To 10) As Integer
Dim r(1 To 10) As Integer
For i = 1 To 10
If Text1.Item(i).Text <> "" Then
'If CInt(Text1.Item(i).Text) = ture Then
r(i) = CInt(Text1.Item(i).Text)
Else
r(i) = 26
End If
Select Case s(i)
Case 1
q(i) = a(i) + b(i)
Case 2
q(i) = a(i) - b(i)
Case 3
q(i) = a(i) * b(i)
Case 4
q(i) = a(i) / b(i)
End Select
Label5.Item(i).Visible = True
If r(i) = q(i) Then
u = u + 10
Label5.Item(i).Caption = "正确"
Else
Label5.Item(i).Caption = "错误"
End If
Next
Label6.Visible = True
Label6.Caption = "您的成绩" + CStr(u) + "分"
End Sub
