| Measurement is only linear. |
Double the dimensions of an object and they think the csa and volume also double - they find the fact that csa increases by a factor of 4 and volume (and therefore the mass) by a factor of 8 surprising. |
| Any quantity can be measured as accurately as you want. |
.... all you have to do is use a modern 'digital' instrument - they think 'old' instruments are out of date and useless. They find the accuracy of precision instuments being related to construction difficult to understand - it needs to be 'new' and 'electronic' to be any good in their eyes! |
| Children who have used measuring devices at home already know how to measure with them. |
You can't teach an old dog new tricks - if they have done it at home - or been show it at primary school they do not listen when you go through how to use it! |
| Imperial measurements are inaccurate |
....all down to 'old' is inaccurate way of thinking! |
| You can measure to any proportion of the smallest unit shown on the measuring device. |
They think they can estimate a third or quarter of a scale division - put them right on this! |
| You should start at the end of the measuring device when measuring distance. |
Zero errors due to 'bashed' metre rulers always give a problem - so do ones that are constructed with a 'gap' to allow for wear and tear! |
| Some objects cannot be measured because of their size or inaccessibility. |
They think a n object must be "touched" to measure it. Use of trig to measure the height of a tree is sometimes suspect! |
| Mass is a quantity that you get by weighing an object. |
In general speak they are interchangable - to a pupil so are their units and numerical values! |
| The five senses are infallible. |
Optical illusions are good on this one! |
| There is only one way to measure perimeter. |
.... and that is 'all of the way' round - mathematical calculation is suspect! |
| Only the area of rectangular shapes can be measured in square units. |
The idea of measuring a circle in square units give some children problems |
| Surface area can be found only for two-dimensional objects. |
Surface area is a concept used only in mathematics classes! Practical making of wrapping for an object helps with this - it is limited to rectangular shapes, but it helps - they have done 'nets' in maths. |
| You cannot measure the volume of some objects because they do not have "regular" lengths, widths, or heights. |
They need to think of volume as an occupied 'space' rather than a mathematical construct - displacement can experiments are fun! |
| The density of two samples of the same substance with different volumes or shapes cannot be the same. |
Density is a concept difficulty for many... practical hands on experience is vital. |
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