Looping and For Next within an IF

I have the For Next statement working to sum all numbers up to value of n, but when I try and accomplish the same thing with Do While Loop and Do Until Loops I get iteration errors that crash my excel. I want the code to continue to work for the ElseIf of summing only even numbers to n and only odd numbers to n, but I'm wondering if it is an issue with the way I typed it or if these loops can't go within the IF statement.

If optsa.Value = True Then
Cells(6, 4) = "Sum All"
sum = 0
i = 0
For i = 0 To n Step 1
sum = sum + i
Cells(8 + i, 2) = i
Cells(8 + i, 3) = sum
Next i
lblfn.Caption = sum
'Do While Sum All
sum = 0
i = 0
step = 0
Do While i <= n
sum = sum + i
step = step + 1
Cells(8 + step, 4) = sum
i = i + 1
Loop
lbldw.Caption = sum
'Do Until Sum All
sum = 0
i = 0
step = 0
Do Until i > n
sum = sum + i
step = step + 1
Cells(8 + step, 5) = sum
i = i + 1
Loop
lbldu.Caption = sum

'ElseIf etc
End If

Hello
We should see your workbook (you forgot to upload it to the Forum).
But it seems to me that it is not necessary to do iterations to get what you are looking for.

B1-TS.xlsm
The assignment is to use all three functions For Next, Do While, and Do Until. I want to put it in an if statement that will decide if it is sum all numbers, sum all even numbers, or sum all odd numbers to a nth number. At the moment the file is crashing because the looping doesn't stop after reaching n. The For Next is working. I also have only been trying to make the sum all work so I am not sure the even and odd codes are correct for those.

Hello,

some school assigment for the slowest way which has no sense according to Excel design …

Something like this perhaps

Sub Sumall()
Call SumForNext(2, 10)
Call SumDoWhile(4, 10, "odd")
Call SumDoUntil(6, 10, "even")
End Sub

Sub SumForNext(col As Integer, n As Integer, Optional OddEven As String)
OddEven = UCase(OddEven)
For i = 0 To n
    If OddEven = "" Or (OddEven = "ODD" And i Mod 2 <> 0) Or (OddEven = "EVEN" And i Mod 2 = 0) Then
        Sum = Sum + i
        Cells(8 + j, col) = i
        Cells(8 + j, col + 1) = Sum
        j = j + 1
    End If
Next i
End Sub

Sub SumDoWhile(col As Integer, n As Integer, Optional OddEven As String)
n = 10
i = 0
OddEven = UCase(OddEven)
Do While i <= 10
    If OddEven = "" Or (OddEven = "ODD" And i Mod 2 <> 0) Or (OddEven = "EVEN" And i Mod 2 = 0) Then
        Sum = Sum + i
        Cells(8 + j, col) = i
        Cells(8 + j, col + 1) = Sum
        j = j + 1
    End If
    i = i + 1
Loop
End Sub

Sub SumDoUntil(col As Integer, n As Integer, Optional OddEven As String)
n = 10
i = 0
OddEven = UCase(OddEven)
Do Until i > 10
    If OddEven = "" Or (OddEven = "ODD" And i Mod 2 <> 0) Or (OddEven = "EVEN" And i Mod 2 = 0) Then
        Sum = Sum + i
        Cells(8 + j, col) = i
        Cells(8 + j, col + 1) = Sum
        j = j + 1
    End If
    i = i + 1
Loop
End Sub