HP 40gs HP 39gs_40gs_Mastering The Graphing Calculator_English_E_F2224-90010.p - Page 19

Exploring the keyboard The first step in efficient use of the calculator is to familiarize yourself with the mathematical functions available on the keyboard. If we examine them row by row, you will see that they tend to fall into two categories - those which are specific to the use of aplets, and those which are commonly used in mathematical calculations. The screen keys The first row of blank keys are context defined. The reason they have no label is that their meaning is redefined in different situations - they are the 'screen keys'. The current meaning of each key is listed in the row of boxes at the bottom of the screen. A common abbreviation used for these keys is SK1 or SK2 etc (for "screen key 1" ). In the PLOT view shown right, some of the screen keys are labeled, such as the key. When you press this key the row of screen keys labels in the PLOT view appear or disappear. To see another view where all the keys are in use, change to the APLET view. Calculator Tip Develop the habit of checking the screen to see if any of those keys have been given meanings. In many views, the screen keys have been set up with useful shortcuts and functions. Aplet related keys The next two rows of keys and part of the third are mainly aplet related, so we'll deal with them as a group. The arrow keys The arrow keys on the right are used in most views, usually to move the cursor (a small cross) or the highlight around on the screen. 19