# Measurement: Level 3

The key idea of measurement at level 3 is that the attributes of an object can be measured against a standard scale.

At this level, students will be constructing their own scales as well as using standard scales for the range of measureable attributes such as length, angle, temperature and capacity. To carry out measurement tasks successfully using standard scales, students need to understand that the scale itself is comprised of a series of individual units that have been repeated. The scale on a measurement tool such as a 30cm ruler performs the same function as a succession of individual units.   In particular it is important that students realise it is the spaces in a scale that are important, not the marks or numbers.  Once students have this understanding they will be appreciate the need to align one end of the object being measured with the start of the scale.

Scales can be presented in a variety of ways. Students are usually first introduced to scales with one-unit increments, but they also need to understand and be able to use scales in which the increments are more than one unit. For example, the small cups used to measure medicine doses often have a scale marked out in increments of 5ml.

When faced with measurements which are not whole numbers of units, students usually use fractional parts of units, such as halves or quarters to quantify the attribute. An alternative approach, which is sometimes used in everyday situations, is to use a smaller unit for the measurement task.  Students should be becoming more aware of the size of standard units in order to make consistent estimates of measurements, and will realise the importance of estimating.

This key idea develops from the key idea of measurement at level 2 which involves the use of non-standard and simple units.

This key idea is extended to the key idea of measurement at level 4 where students apply multiplicative thinking to measurement in order to carry out conversions between units, and calculate simple derived measures such as area.