Calculate - Texas Instruments Cabri Geometry II Manual Book

Calculate

The Calculate tool opens a calculator at the bottom of the screen. You can perform calculations
using measurements, numerical values, calculation results, and numerical inputs from the
keyboard. When you change the components of a calculation, the result is updated.
The calculator shown below is displayed at the bottom of your computer screen. It cannot be
moved from this position. Once selected, the calculator remains ON (visible) until you press the
OFF button. The calculator becomes active as soon as you select the Calculate tool. It becomes
inactive when you perform any action not directly associated with a calculation. To reactivate the
calculator, you can either select the Calculate tool or click in the calculator edit window.
Calculations are entered in the edit window. See the procedure "Entering a calculation" in this
section for how to enter a calculation. A measurement or numerical value from the Cabri
Geometry II drawing window is represented in the edit window as a variable a, b, c, ..., z. This
variable is also shown next to the value in the Cabri Geometry II drawing window. The value's full
precision will be used in the calculation. All parentheses must be closed when entering a
calculation.
You can extract the abscissa and ordinate from any coordinate set by clicking on each value
individually.
The calculation result is displayed in the result window. You can drag the result to the Cabri
Geometry II drawing window. When you drag the result to the drawing window, a tag identifying it
as a calculation result is dragged along with it. See the step for copying the result to the drawing
window in the procedure "Entering a calculation" on page 11-10.
You cannot modify values in the result window. However, on the Macintosh and Windows
versions, you can edit results using Numerical Edit once they are in the drawing window. In addition
to using the standard Numerical Edit features, you can display and change the composition of the
result by selecting the Calc option in the Numerical Edit window. For the DOS version, select the
Calculate tool, and double-click on the result to get the original formula back in the edit window. If
you change the composition of a calculation, its result is automatically updated in the drawing
window. (See " Numerical Edit" in the chapter "Using the Display Toolbox" for more details.)
If two different but compatible units are involved in a calculation, the result is displayed with the
default units specified in Preferences under the Options menu (for example, 2 cm + 4 mm = 2.4 cm).
The calculator gives three types of warnings:
4
division by zero
4
parentheses not closed
4
incompatible units
Both division by zero and parentheses not closed must be corrected before the calculation can be
performed. For incompatible units , Cabri Geometry II offers the option to disregard the units and to
perform the calculation as if the values were without units.
Copying permitted provided TI copyright notice is included
© 1997, 1999 Texas Instruments Incorporated
edit window
Chapter 11: Using the Measure Toolbox
result window
11-7