:P
Fixed
Cost
Price DWN
Profit
Quantity
Figure 7 Menu Map of the Break-even menu
There are four types of menu items:
1.Read/write. Read/write menu items, such as Fixed in the Break-even menu shown above, are easily recognizable, because when they are selected, both the INPUT and small (=) annunciators are lit. When lit, these annunciators indicate that keying in a number and pressing Iwill store the entered number in the displayed menu item. Pressing =(outside of a mathematical operation) calculates the value for that item based on available data.
2.Read-only. Read-only items such as Internal Rate of Return (IRR% ) in the IRR menu are display-only; they are values computed internally by the calculator.
3.Write-only. Write-only items, such as investment interest rate (Inv. I% ) in the Net Present Value (NPV) menu, are similar to read/write items in that the INPUT annunciator is lit when these items are selected, indicating that keying in a number and pressing Istores that number in that menu item. However, the =key does not calculate a value for that item.
4.Special items. Special items, such as the Degree/Radian option in the Mode menu, the items of the Reset menu, and the items of the Percent Calculation (%calc ) menu perform an action when Iis pressed. Depending on the menu, this action can be the
selection of a sub-menu (%calc), changing a mode or setting (Mode menu), or erasing data (Reset menu)