Lesson idea. Numbers that are too big for the calculator's 10digit display are shown in standard index form. Many calculators now use Ć10n but older calculators may use āEā in the display instead. This activity is for secondary school pupils who are unfamiliar with standard index form. It is an intriguing one hour investigation where pairs of students explore the way a calculator converts numbers. They may well find out how it works for themselves.
Teaching approach. The Standard Index Form is a key idea for mathematicians and scientists. The notion that we choose to write numbers in this way requires some explanation. So in this activity, pupils take part in an investigation^{(ta)} on how standard index form works. This is a higher order^{(ta)} problem solving context where students are encouraged to engage in mathematical thinking^{(ta)}. They may be involved in whole class^{(ta)} or small group work^{(ta)} discussion^{(ta)}, so they have a good opportunity to practice using mathematical language^{(ta)} and questioning^{(ta)}. This means that students do not need to be able to explain their ideas in full: they can use the calculator's feedback to discover whether their ideas are correct or not. This is also an exciting way for pupils to realise an initial idea that fits the data may need to be extended when new data arises. This resource therefore aims to develop investigative skills, as well as introduce pupils to standard index form in a memorable way. The pupils can later use their knowledge of indices in discussion^{(ta)} and group talk^{(ta)} as they explain what is happening. ^{(edit)}
Resource details  
Title  An Introduction to the Standard Index Form 
Topic  Standard Index Form 
Teaching approach  
Learning Objectives  Students should be able to:

Subject  
Age of students / grade  
Additional Resources/material needed  This was written for use with TI82 Graphical Calculators, but new scientific calculators can also be used.

Other (e.g. time frame)  This activity will take at least an hour. 
Files and resources to view and download  The Introduction to standard index form/Teacher Notes contains teacher notes, a PowerPoint presentation and an Excel worksheet to be used for an activity on numbers in the solar system. All three files are also available to download: 
Acknowledgement  This resource was adapted from resources contributed by Mark Dawes 