Preferred Materials

Calculating Changes assumes that students at all levels have open access to Poly Plug and calculators. Activities can be adapted to other resources, but to get maximum benefit from the Calculating Changes professional development programs, schools will need to invest in these resources. Some schools have made that shift by putting Poly Plug on the children's book list.

... Poly Plug

Poly Plug... is colourful, tactile, motivating is classroom savvy - noiseless, easy to pack up is useful as both a structured and an unstructured aid has applications across a broad range of mathematical content - pattern, counting, fractions, graphing, symmetry, problem solving has even more applications when used in conjunction with other simple, readily obtainable material, eg: as an abacus when two boards are used on A3 paper

Poly Plug is also used as a support resource for the Mathematics Task Centre because many of its hands-on tasks can be converted to whole class investigations with Poly Plug. Click here to find out more about Poly Plug from that site, including how to order.

... Calculators
Calculating Changes assumes students have free access to calculators from the day they enter school. This assumption is based on research from the Calculator Aware Number (CAN) project in England, and its derivatives elsewhere.

Given this assumption we want students to use calculators which give correct answers, and the majority of four function calculators in schools don't! - see the activity Order of Operations. However, finding a simple four function machine with this Algebraic Operating System (AOS) is not easy.

MathMaster Manufactured by Stokes Publishing Company, California, this is the only simple keyboard, four function calculator we have found which has the order of operations built in. It also has several other excellent features and is good value for money, but it is not solar powered. The instruction pamphlet included with the machine claims it to be 'the world's finest four function calculator' and if it wasn't for its impractical battery power we could agree. We have contacted Stokes about this issue and the response from their Vice President can be read here. We recommend MathMaster for your next calculator purchase, provided you are aware they are battery powered. Batteries will last some years, depending on usage, but down the track you will have to set time aside to change them. Digits beginning to dim indicate time for a battery change. We have developed a firm and friendly working relationship with Stokes Publishing and believe that they will stand behind their product (something that doesn't happen with less expensive 'Crazy Dave' machines), so if there is any problem other than digits dimming due to weakening batteries, we can direct you to their support network.

MathMaster is available from Objective Learning Materials (OLM).

You can download the operation manual for MathMaster from this page on the Stokes Publishing site. It will give you a good idea of what the calculator can do and how the battery is changed.

If you come across any other simple four function machine with AOS built in, please let us know the details.

TI7 MathMate The Texas Instruments TI 7 MathMate was brilliant, perhaps because it was designed in co-operation with leaders from the Calculator Aware Number project. However, apparently because teachers thought they were too expensive, not enough were sold and the MathMate has been discontinued. The TI 15, which is offered as a replacement, does have order of operations built in but: it is definitely not simple it costs more than the MathMate did it has too many buttons it requires an instruction course to learn to use its features - some of which are worthwhile - and it doesn't fit comfortably into the hand of a five year old. So, if you can find any MathMates somewhere grab them.

... Calculator Choices
Our activities assume children of all ages have open access to calculators. Some activities can work with any machine, however, if the activity involves the possibility of mixing the operations of + or - with x or ÷ simple four function machines will give the wrong answer to most questions. So, use your school calculators if you wish but beware of this limitation.

Alternatively, purchase MathMasters. They are excellent in all respects except power management, so be aware that within two years you will probably have to unscrew the back of every one you buy to replace the fiddly hearing-aid style battery.