Computer can perform
mathematical calculations much faster than human beings. However,
computer itself will not be able to perform any mathematical
calculations without receiving instructions from the user. In
VB2010, we can write code to instruct the computer to perform
mathematical calculations such as addition, subtraction,
multiplication, division and other kinds of arithmetic operations.
In order for VB2010 to carry out arithmetic calculations, we need to
write code that involve the use of various arithmetic operators. The
VB2010 arithmetic operators are very similar to the normal
arithmetic operators, only with slight variations. The plus and
minus operators are the same while the multiplication operator use
the * symbol and the division operator use the / symbol. The list of
VB2010 arithmetic operators are shown in table 7.1
below:
sTable 7.1: Arithmetic
Operators
Operator 
Mathematical
function 
Example 
+ 
Addition 
1+2=3 
 
Subtraction 
41=3 
^ 
Exponential 
2^4=16 
* 
Multiplication 
4*3=12,
(5*6))2=60 
/ 
Division 
12/4=3 
Mod 
Modulus (return the
remainder from an integer division) 
15 Mod
4=3 255 mod
10=5 
\ 
Integer Division
(discards the decimal places) 
19\4=4  

Example 7.1
In this program, you need to insert two
Textboxes, four labels and one button. Click the button and key in
the code as shown below. Note how the various arithmetic operators
are being used. When you run the program, it will perform the four
basic arithmetic operations and display the results on the four
labels.
Private Sub
Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim num1,
num2, difference, product, quotient As Single num1 =
TextBox1.Text num2 = TextBox2.Text
sum=num1+num2
difference=num1num2
product = num1 * num2
quotient=num1/num2
Label1.Text=sum
Label2.Text=difference
Label3.Text = product
Label4.Text =
quotient
End
Sub
Example 7.2
The program can use Pythagoras Theorem to calculate
the length of hypotenuse c given the length of the adjacent
side a and the opposite side b. In case you have forgotten the
formula for the Pythagoras Theorem, it is written
as
c^2=a^2+b^2
Private Sub
Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim
a, b, c As Single a = TextBox1.Text b =
TextBox2.Text c=(a^2+b^2)^(1/2) Label3.Text=c
End Sub
Example 7.3: BMI Calculator
A lot of people are
obese now and it could affect their health seriously . Obesity has
proven by the medical experts to be a one of the main factors that
brings many adverse medical problems, including the the heart
disease. If your BMI is more than 30, you are considered
obese. You can refer to the following range of BMI values for your
weight status.
 Underweight = <18.5
 Normal weight = 18.524.9
 Overweight = 2529.9
 Obesity = BMI of 30 or
greater
In order to
calculate your BMI, you do not have to consult your doctor, you
could just use a calculator or a home made computer program, this is
exactly what I am showing you here. The BMI calculator is a Visual
Basic program that can calculate the body mass index, or BMI of a
person based on the body weight in kilogram and the body
height in meter. BMI can be calculated using the formula weight/( height
)^{2}, where weight is
measured in kg and height in meter. If you only know your weight and
height in lb and feet, then you need to convert them to the metric
system (you could indeed write a VB program for the
conversion).
Private Sub
Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArsgs) Handles Button1.Click
Dim
height, weight, bmi As Single height =
TextBox1.Text weight = TextBox2.Text bmi = (weight)
/ (height ^ 2) Label4.Text = bmi
End
Sub
The output is
shown in the diagram below. In this example, your height is
1.80m( about 5 foot 11),your weight is 75 kg( about 168Ib), and
your BMI is about 23.14815. The reading suggests that you are
healthy. (Note; 1 foot=0.3048, 1 lb=.45359237 kilogram)
From the above examples, you can see that
perform arithmetic operations is relatively easy. Here are more
arithmetic projects you can try to programs:
 Area of a triangle
 Area of a rectangle
 Area of a circle
 Volume of a cylinder
 Volume of a cone
 Volume of a sphere
 Compound interest
 Future value
 Mean
 Variance
 Sum of angles in polygons
 Conversion of lb to kg
 Conversion of Fahrenheit to
Celsius
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