Fat Gram Calculator

[gir489]

I'm trying to do a project from a book, and I have no idea what it's telling me to calculate, other than it's a percentage.

Here's what it states:

One gram of fat has 9 calories, so:
Calories from fat = fat grams * 9

the percentage of calories from fat can be calculated as:
Percentage of calories from fat = Calories from fat total calories

This is what my professor wrote in my book when I asked him for help about understanding what it was asking for:

cal_fat = fat_gr(txtbox2) * 9
perc_fromfat= calfat (over) cal_total<--- (txtbox1)
= cal_fat/cal_total

Here's the code:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim FatTimes9 As Integer
Dim FatPercent As Integer
If Val(txtFat.Text) > Val(txtCalories.Text) Then
MessageBox.Show("Calculation Error", "Calculation Error")
txtTotal.Clear()
End If
If Val(txtCalories.Text) < 1 Then
MessageBox.Show("Value not greater than 1", "Input Error")
txtTotal.Clear()
End If
FatTimes9 = Val(txtFat.Text) * 9
FatPercent = FatTimes9 / Val(txtCalories.Text)
txtTotal.Text = FormatPercent(FatPercent)
End Sub

The examples in the book say:

200 calories, 8 fat grams = 36%
150 calories, 2 fat grams = 12%
500 calories, 30 fat grams = 54%

EDIT: Nevermind. I figured it out. Since I set the FatPercent dimension to an integer, instead of a single, it was rounding off to the nerest whole number, thus giving me a 0.