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When your pupils tackle questions that involve conversions, do they knowwhat’s actually being asked of them? RichardColes isn’t so sure… T he purpose of this article is to consider the way we, as maths teachers, deliver content to our students and why we do what we do. Questions will be posed throughout, alongside examples to highlight my thinking when planning and delivering the topic of conversions, though the points could easily be applied to other topics that suffer from similar misconceptions. In recent years there has been a decline in pupils’ conceptual understanding of conversions. Across all exam boards in 2019, it emerged that pupils at both Foundation and Higher level answered questions about conversions poorly. Defined as ‘A change in the form of a measurement, different units, without a change in the size or amount,’ the etymology of the word derives from the Latin  conversionem (‘A turning round, revolving; alteration, change’); a noun of action from the past- participle stem convertere  (‘To turn around; to transform,’); from the assimilated com (‘with, together’); and vertere (‘to turn’). Why might students find conversions difficult? We live at a time where we’re plagued by a combination of imperial and metric units. We measure our speed when driving in miles per hour, but compete in 5km park runs on Saturday mornings. We measure our height in feet and inches, but weigh ourselves in kilograms. Children barely know if they’re coming or going with regards to knowing what any given unit is, let alone how to convert it. Complex vocabulary It’s sometimes easy to assume that students don’t answer questions correctly because they don’t understand the methods required, or the content, yet the language of the question also requires decoding. Do we spend enough time breaking down question phrasing and vocabulary? The work of Beck and McKeown refers to different tiers of vocabulary that increase in complexity, but are all essential for students if they are to understand exam questions. In essence, tier 1 vocabulary is everyday language that will be familiar to all students (e.g. ‘unit’). Tier 2 vocabulary is more complex, perhaps not part of everyday speech, but likely to be found in academic text across different subjects (e.g. ‘equivalent’). Tier 3 vocabulary is subject-specific and specialist (e.g. ‘algebra’). We can generally ignore tier 1 words and assume understanding, and will naturally tend to focus on our own subject’s tier 3 key terms. However, we also need to spend time developing confidence with tier 2 words, as these are powerful for helping to decode exam questions. Concepts and formulas Let’s look at three examples from AO1-3 and consider how to deliver them, beginning with this AQA AO1 question: What metric unit should be used when giving the distance from London to Liverpool? + Kilometres + Miles + Meters What Tier 3 words are needed to understand this question? Do the students know what is meant by a kilometre, mile and metre? We should then consider the students’ understanding of those Tier 2 words. I’ve seen many experienced teachers, including myself, assume that students know these already – but do they? Take ‘distance’, for example. Do we explicitly tell pupils the meaning, or simply assume they know it? What metric do pupils use for distance themselves in their daily lives? Did they make the link between ‘metric’ and ‘metre’ in the question? Do they even have any knowledge of where London and Liverpool are in relation to each other? In many trials of this question pupils selected ‘miles’, due to them having often been in cars and knowing that signposts display distances in miles. Let’s examine a second example. A car travels 192.5 km in 3 hours and 45 minutes. What is the average speed of the car? Key items to consider here include the way formulas can differ between maths and science departments. How 32 teachwire.net/secondary “What’s a kilometre?” 8 STEPS TO IMPROVED ATTAINMENT 1 Consider the phrasing and vocabulary used within questions 2 Ensure pupils fully understand all tier 2 words, as well as tier 3 3 Employ an effective delivery that takes into account pupil starting points 4 Don’t skip the basics – ensure your starters recap prior knowledge 5 Use a variety of skilful questioning techniques to ensure pupils understand key concepts prior to attempting questions themselves 6 Present a variety of questions in different contexts, using different phrasing and at different levels of AO1, AO2 and AO3 7 Check that pupils are fluent with all success criteria set out at the start before moving on 8 Build in opportunities for recall and retrieval throughout your curriculum and lesson sequence to ensure overlapping and repetition of the basics