Dim average As Single ' this makes the "average" variable.
    Dim total As Single   ' this makes your "total" variable.
    Dim number1 As Single ' this makes "your first numbers" variable.
    Dim number2 As Single ' this makes "your second numbers" variable.
    Dim number3 As Single ' this makes "your third numbers" variable.

    number1 = InputBox("What's the first number?") ' this asks for your first number.
    number2 = InputBox("What's the second number?") ' this asks for your second number.
    number3 = InputBox("What's the third number?") ' this asks for your third number.

    total = number1 + number2 + number3 ' this calculates your total number by adding all three numbers together.
    average = total / 3                 ' this calculates your average by diving your total number by 3
    MsgBox("your average is: " & average) ' this displays "your average is:" *and then your average number