Computer Algebra Systems: An Introduction 
 
© R. Meisel, April 7, 2007 
What is a CAS? 
 
A computer algebra system (CAS) is a program on a calculator or a computer 
that can perform algebraic manipulations. The CAS may also be known as a 
symbolic manipulator. 
 
Starting a CAS 
 
1. Press the ON key to turn the 
calculator on. If you don't see the 
Home screen, press the HOME 
key. The Home screen will 
appear. 
 
2. Before using the CAS, it is 
wise to clear the calculator of any 
values left in the memory by a 
previous use or user. Press 2nd, 
then F1, to access the F6 or 
Clean Up menu. Select 
2.NewProb. Press ENTER.  
 
3. Try some calculations to familiarize yourself with the keyboard and display. 
 
a) 5(7 – 3)
3
  Answer: 320 
 
b) π(4.2)
2
    Answer: 55.42 
 
c) –
25  – 3    Answer: –8 
 
Tech Tip: If you press a key in error, you can usually cancel its effect by 
pressing the ESC (Escape) key. 
 
Keep in mind the difference between the negative key (-), which makes a number 
negative, and the subtract key, which is used between two operands.