1.

Go to the Calculator application, and tap the entry line to show the keyboard.

2.

Tap Tools .

3.

Go to Actions, and then tap Lock.

4.

Tap Lock Variable to select the function and insert it into the entry line.

5.

Tap , and then tap the variable name you want to lock.

Note: You can also type the variable name in the entry line.

6.

Tap ENTER.

The result Done indicates the variable is locked.

Locked variables display a lock icon on the variable menu list.

Note: The Lock command clears the Redo/Undo history when applied to unlocked variables.

 

To modify or delete a locked variable, you must unlock the variable.

1.

Tap Tools and go to Actions > Lock.

2.

Tap Unlock Variable to enter the function into the entry line.

3.

Tap , and then tap the locked variable name.

4.

Press ENTER to remove the locked status.

The result Done indicates the variable is now unlocked.