Recent postsView all

Exam Season
13 Apr 19
Compound Interest
23 Dec 18
This Years projects 2018
14 Sep 18
Final Report to teachers
17 Jun 18
Problems with surveys
7 Jun 18
20 May 18
May TZ2 exams
10 May 18
Subject report and IA
1 Mar 18
New Curriculum
10 Feb 18
24 Sep 17
First Draft Feedback
1 Jul 17
Venns in the news
23 May 17

Making Calculators

Friday 22 November 2013

Using spreadsheets for understanding

This is something I find myself doing increasingly often so I thought I would outline the quick idea here in a blog post and work on developing the ideas in to classroom activities. The idea is easily explained. Spreadsheets can easily be designed and programmed to perform certain functions that your calculator can. The question is, why would we bother when we have calculators that can do it for us? The answer is that the process of designing and programming to simulate calculator function requires a really thorough understanding of the mathematics behind the process and takes the mystery away from how the calculation is done. I have found that in asking students to do this task they have really developed some sound understanding and had some great discussion in the process of trying to do it.

Where can we do this?

Here are a few ideas...

  • Create a compound interest calculator where you can change the interest rate, intial investment, compounding period and length of investment and watch the the final amount change accordingly.
  • Create a chi² statistic calculator for diferent contingency tables. Start with a 2 x 3 for example. The user changes the numbers in this table, the totals change accordingly, a second table of expected frequencies is automatically calculated. A third table will process the difference in these and calculate the chi² statistic.
  • A linear regression machine - Set up a spreadsheet to calculate the correlation coefficient and regression line for a set of 20 ordered pairs, such that you can change any of the numbers and see the change propogate.

There are more applications of this idea and they dont necessairly have to be done with spreadsheets. See this example of the trig calculator to see how dynamic geometry can be used to create a trig ratio calculator. the main point is that the programming of these calculators is a rich tasks that requires students to really explore with the mathematics and reason with each other to make them behave properly! I am planning to develop these in to classroom activities and will post links here when I have!

La Face
30 Dec 2013
IA Issues
10 Oct 2013


To post comments you need to log in. If it is your first time you will need to subscribe.