# Arithmetic Operations

The value of a scroll bar can only be integer. Let's suppose you would like to write a program that lets the user select the cost of a meal and then displays the amount of tip.
We would like to let the user select an amount from 0 to \$100.00.
The solution is to make the Maximum value of the scroll bar 10000.
When an amount is selected, the value is divided by 100 to give the desired values.

Start a new program and call it Tip. Build the form as shown in the illustration with the following names and properties:

### Labels :

lblInstructions with the text "Select the cost of the meal:"
lblCost with the text "\$0.00"
lblTip with the text "Leave a tip between"
lblTip1 with the text "\$0.00"
lblAnd with the text "and"
lblTip2 with the text "\$0.00"

### Horizontal Scroll Bar :

hsbCost with the following properties:

• Maximum: 10000
• LargeChange: 1

Write the code for the change event on the scroll bar:

```private void hsbCost_Scroll(object sender, ScrollEventArgs e)
{
// Tip is between 15% and 20%
double cost = this.hsbCost.Value / 100; // divide value by 100 to get 2 decimal places
lblCost.Text = cost.ToString("\$0.00"); // format numbers to 2 decimal places
double tip1 = cost * 0.15; // 15% tip
lblTip1.Text = tip1.ToString("\$0.00"); // format with 2 decimal places
double tip2 = cost * 0.2; // 20% tip
lblTip2.Text = tip2.ToString("\$0.00"); // format with 2 decimal places
}```
Notice that if the value selected on the scroll bar is 900, for example, cost will display as \$9.00