By the help of a calculator we can carry out complicated mathematical operations quickly and accurately. Calculator proponents claim that calculators simplify tasks and allow students to spend less time on monotonous calculations and more time on understanding problems and determining the best methods for solving them; calculators allow students who would normally be turned off to math because of dissatisfaction or boredom to increase their mathematical understanding. Furthermore, every teacher of mathematics knows that there are graduating pupils in primary school who had not mastered the multiplication table, have difficulties with subtraction within the limits of 20 and so on. Give all of them calculators and they will obtain desirable result without sweating, puffing and having a dread of mistakes and therefore will become more confident about their math abilities.



But this good-looking picture is too charming to be a realistic one. There are several circumstances which make using calculators at school not so attractive. Firstly even a brand new modern calculator which has amazing computational power is a device only. Each calculator is as good and as accurate as its operator. To use it in proper way a pupil must know its manual well. Calculators of different kinds use different orders for carrying out mathematical operations, pressing keys, and their manuals have a bad habit to get lost. It is very easy to make simple mistakes when using one. You must think of the rough size of answers, so that you can see if an answer is sensible or not. To avoid mistakes you must repeat all calculations. If you get two different answers, then you must repeat all calculations for the third time.

Very often even advanced students make mistakes – pressing wrong buttons, forgetting to change a mode, rounding values too soon, forgetting to use brackets rightly … And what about bad achieving pupils? Can you imagine that a pupil who does not know what brackets are for can use them correctly? How can a kid who cannot mentally multiply 8 by 7 weighs up a result?

For advanced students a calculator is a comfortable vehicle, which helps him to reach their aim more rapidly and more easily, but in case of need they can go out of it and move themselves. And what is more they very often perform better without a calculator since in many cases mental computations are quicker, easier and more errorless then computations with calculator.

Whereas for bad achieving pupils a calculator is a motored wheel chair for cripples, without which they cannot move. They are afraid to carry out mentally simple arithmetical operations and waste precious time when pressing keys.

Besides that there is another significant hazard. A person who all the time uses a calculator gradually loses his/her mental computational skills. Very often even advanced pupils take calculators when they need to make simple computations which can be easily implemented in head. Their brains slowly but surely get accustomed to walking on crutches and became indolent to use mental computational abilities, whereas skills, which are not used, became forgotten very soon. In certain cases it leads to difficulties in math's learning.

Both my experience (32 years in the classroom) and my investigations (20 years of studies) shows that pupils with unsteady elementary mental computational skills (addition and subtraction within the limits of 20, multiplication and division within the limits of 100) have great difficulties while learning the other basic topics of arithmetic and algebra. In other words they are doomed to poor progress in school math. Even calculators cannot help them. If you want to see some figures and diagrams you can read my article “Influence of a Level of Elementary Mental Computation Skills upon Success in School Mathematics” at my web site Prevention of Failure in School Mathematics (reference – My Articles).

Do not think that I am trying to stop progress and calling to finish with any computing stuff at school. It is obvious that we can not manage without calculators today, but we must remember about simple mental computations and their significance for success or failure in math. I consider that it is necessary to lay emphasis once more – extensive using of calculators (especially at the first six or seven grades) leads to degeneration of pupils' mental computational skills and afterward to deterioration of their learning ability. This is the main hazard of using calculators at school.