Tapping into mathematics
Tapping into mathematics

This free course is available to start right now. Review the full course description and key learning outcomes and create an account and enrol if you want a free statement of participation.

Free course

Tapping into mathematics

1.2 Second functions

Notice that almost every key has more than one purpose or function. The main function is written directly on the key; but notice that written above the key, there is often another function. This is the second function for that key and is activated by first pressing and releasing the second-function key near the top left-hand corner of the keyboard. For example on the TI-84, OFF is the second function for the ON key: you press 2nd [OFF] to turn the calculator off.

On some calculators, some keys also have third functions, written above them. For example you may be able to type letters of the alphabet by first pressing an key.

This module uses the notation, similar to that used in the TI Guidebook, where the main function keys, like ON, are written in bold, whereas second function keys, like OFF, are written inside square brackets as in 2nd[OFF]. The number keys and alphabetic symbols are in bold type: for example, 8.


Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to university level study, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus