# Measurement: Level 6

The key ideas measurement at level 6 are the concept of the accuracy of a derived measure and the understanding that abstract mathematical formulae may be used to solve problems.

Accuracy of measurement is an important element in measuring.  It is important to know both how accurate a derived measure needs to be and how accurate the measuring device can be in a given situation.

Similarly, accuracy specified in terms of number of significant figures allows students to see equivalence of levels of accuracy within different metric units.  For instance, there is no difference in the level of accuracy between 4.80 metres and 480 centimetres even though one may appear to be more precise than the other.

At level 6 students are also able to apply formulae relating to simple three-dimensional figures.  This enables unknown dimensions of common objects to be determined.  Because of their difficulty these formulae may be introduced without proof or formal derivation in order for them to be used to solve problems. So now students need to know how to use, and understand the relevant parts of a formula and they also need to know how to select the appropriate formula.  This may mean checking a formula’s dimensions so that, for instance, they do not use an area formula to measure volume.

This thread follows on from the key idea of measurement at level 5, and the key idea of shape at level 5 where there has already been an introduction to three dimensional objects.

Applications of this thread can be found in calculus as well as in science.