VB.Net guess user's number from 1 to 1000 - vb.net

Question

I am trying to create a guessing game that guesses the user's number from 1 to 1000. The user inputs if the number is higher or lower than the computer's guess. Based on the user's input, the computer each time halves the amount of the guess (e.g. first guess is 500, second is 250, third 125, etc, etc)
However I have encountered a problem when I am running this program. After pressing 'higher' or 'lower' for a few times, I am unable to change the output any further. I suppose this is to do with amount = amount / 2 reaching a limit where it can barely be added or subtracted into intGuess. I have tried doing amount = (amount / 2) + 1, but that sometimes doesn't allow me to get to a number.
How would I counteract this problem?
Here is my code:
Dim intGuess As Integer = 500
Dim amount As Integer = 500
Dim count As Integer = 0
Private Sub btnLower_Click(sender As Object, e As EventArgs) Handles btnLower.Click
amount = amount / 2
intGuess = intGuess - amount
lblGuess.Text = $"Is your number {intGuess} ?"
count = count + 1
End Sub
Private Sub btnHigher_Click(sender As Object, e As EventArgs) Handles btnHigher.Click
amount = amount / 2
intGuess = intGuess + amount
lblGuess.Text = $"Is your number {intGuess} ?"
count = count + 1
End Sub
Just thought I should add this, but the first guess is 500.

Answer 1

I play this game verbally with my young son. I tell him to guess a number from 1 to 1000 and guarantee I can guess it in 10 or fewer guesses. It is a simple binary search. You can research binary search to come up with an algorithm. It's pretty simple and I've split it up into buttons like you have. Here is my form
The code to make it work is
Private guess As Integer
Private max As Integer
Private min As Integer
Private Sub StartButton_Click(sender As Object, e As EventArgs) Handles StartButton.Click
If Integer.TryParse(MaxTextBox.Text, max) AndAlso
Integer.TryParse(MinTextBox.Text, min) AndAlso
max > min Then
makeGuess()
Else
MessageBox.Show("Error in max or min, cannot continue! Fix max and min and try again.")
End If
End Sub
Private Sub HigherButton_Click(sender As Object, e As EventArgs) Handles HigherButton.Click
min = guess
makeGuess()
End Sub
Private Sub LowerButton_Click(sender As Object, e As EventArgs) Handles LowerButton.Click
max = guess
makeGuess()
End Sub
Private Sub JustRightButton_Click(sender As Object, e As EventArgs) Handles JustRightButton.Click
MessageBox.Show($"That's right, I found your number, it is {guess}!")
End Sub
Private Sub makeGuess()
guess = CInt((max - min) / 2 + min)
GuessLabel.Text = guess.ToString()
End Sub