Calculator Experts

Years K - 6


This simple idea comes from Tich Ferencz, a secondary teacher in Tasmania. How well it works will depend on the degree to which you provide time for exploration, and the degree to which you demonstrate that you value the activity by encouraging and celebrating student discoveries. The activity can be applied to scientific and graphic calculators. Suitable for threading.

Members can extend this activity with ideas in What Can You Do With...How Can You Show Me?, and Bothering With Brackets. The first of these includes an example of a child's work recorded in Calculators, Children and Mathematics, the report of the Calculator Aware Number (C.A.N.) project. (See Calculating Changes Background for more information on this UK project. Members can find additional information in Advice from the C.A.N. Report.)


  • One calculator per student.
If you would like to know more about the calculator shown see Preferred Materials. Closer inspection shows it has features that other simple four function machines don't have. One unique one is the key eliminator function which can temporarily prevent a key from operating. See the activity Broken Calculator for an explanation of the educational value of such a function.


Ask each student, or pair of students to select a button on the calculator. Tell them that you expect them to become experts in the way that button works. Ask them to find out everything they can about:

  • what it does by itself.
  • what it does in conjunction with other buttons.
  • any situations where it seems to have a special effect.
  • how the calculator would have to be used if this button was not on the calculator.
These questions are likely to generate considerable exploration and discussion in a broad range of content. After all, decimals and negative numbers, for example, which are often 'reserved' for older children are likely to occur in a free exploration that might result in studying the division or subtraction buttons. For example, consider the last few lines of Sarah's work in Predict A Count.

(We would be happy to provide space here to publish any of your students' insights that might help your colleagues see additional value in this activity.)



  • decimal calculations
  • decimal interpretation
  • decimal representation of a fraction
  • negative numbers
  • number line - ordering, operations
  • operations - whole number
  • order of operations
  • pattern generalisation
  • pattern interpretation
  • pattern recognition
  • properties of number
  • recording - calculator
  • recording - written

Calculating Changes ... is a division of ... Mathematics Centre