The National Numeracy Learning Progression element of Measurement and geometry is where we locate the sub-element of Understanding units of measurement. This sub-element helps teachers to develop fine-grain understanding of student numeracy development in measurement, by guiding teachers to support students whose development is above or below stage equivalents in syllabuses.

Understanding units of measurement describes how students: are able to recognise attributes that can be measured; use and calculate with units of measure; make the transition from informal to formal units; develop the structure of units allowing them to calculate length, area and volume; and deal with mass and capacity, using personal referents and estimation skills.

The relationship between units of measurement is commonly applied in decimals, ratio, rates, percentages and proportions found in the sub-elements of: Number and place value (NVP); Multiplicative strategies (MuS) and Proportional thinking (PrT).

As Professor Dianne Siemon suggests in her book Teaching Mathematics:

“Making meaningful measurements and estimating measurements both depend upon a personal fluency with the unit of measurement being used,” and, “Measuring skills are essential to successful numerate behaviour in managing day-to-day situations.”

It is important that we establish not only the links between mathematics and other key learning areas, but also the link between mathematics and numeracy, as these are the connections that create meaningful contexts for extended learning. If we want our students to use their mathematical knowledge ‘in action’ across the curriculum and in everyday life, then it’s important that they have not only the knowledge and skills to do this, but also the confidence to do it.

Maura Sellars explains, students do not automatically learn numeracy skills in mathematics times in classrooms, they need to have multiple opportunities to develop competencies in numeracy by solving real problems. Making explicit linkages and connections and discovering and exploring number and other conceptual relationships helps students to develop robust knowledge that is easily transferred from familiar to unfamiliar contexts and problems. Numeracy, like literacy, is fundamental to students’ capacities to make meaning of their world.

Dianne Siemon believes measuring skills are essential to successful numerate behaviour in managing day-to-day situations.

Juliana would like to have a pathway from her back door to the garden shed. She measures the distance to be 5376 millimetres long. Juliana needs to convert this measurement into metres to purchase an accurate number of pavers for her path.

Let’s consider the steps needed to convert 5376 millimetres into metres. Using a number line and a conversion chart may help Juliana with her calculations.

To convert 5376 millimetres into metres, she must: First, divide by 10 to get to centimetres, then divide by 100 to get to metres. Meaning, 5376 millimetres is equivalent to 5.376 metres.

So where is 5.376 on a number line?

5.376 is between 5 and 6. By zooming in, she can see there are 10 divisions between 5.0 and 6.0.

When she considers 5.376, she knows it is bigger than 5.3, but less than 5.4. 5.376 is between 5.3 and 5.4. By zooming in she can see there are 10 divisions between 5.30 and 5.40.
This means there are 100 divisions between 5 and 6.

When she considers 5.376, she knows it is bigger than 5.37, but less than 5.38. 5.376 is between 5.37 and 5.38. By zooming in she can see there are 10 divisions between 5.370 and 5.380. This means there are 1000 divisions between 5 and 6. She can find the exact position of 5.376 when she divides 5 and 6 up into thousandths.

By zooming out again, she can see where 5.376 is on the number line. By understanding units of length and having a knowledge of decimals, Juliana is able to convert her measurement of 5376 millimetres into 5.376 metres and accurately complete the paving of her garden path.