
Appendix B


Combined Arithmetic Processes


The HP80 performs combined arithmetic operations—serial, mixed and chain calculations—with ease. If you read Appendix A (Design Concepts) you now know how the operational stack works and can apply that knowledge to the following examples.


Automatic Doubling, Squaring

If you want to double or square a number, it’s not necessary to press that number twice. Merely enter the number, save it and press + to double or × to square the number. For example, to double 3,


 Enter:    See Displayed:   


 

3 doubled



The following illustrates the data flow in the stack.



Press  See  Remarks 
3

3.

3 is keyed into X.

SAVE

3.00

3 is loaded into X and Y.

+

6.00

Contents of X and Y are added; result (6) is loaded into X.

 


To square 3,


 Enter:    See Displayed:   


 

3 squared



Again in the stack,



Press  See  Remarks 
3

3.

3 is keyed into X.

SAVE

3.00

3 is loaded into X and Y.

×

9.00

Contents of X and Y are multiplied and the product (9) is loaded into X.

 

