# Into the fourth dimension

What mathematical demands are made on science students?

* judging units and indices (key stage4 and A-level); * drawing graphs and "picturing them" (key stage 4 and A-level); * using logarithms (A-level); * rearrangingtransposingmanipulating equations (KS4 and A-level). Take the following problem: What is the relationship between voltage, current and resistance? Use this to calculate the resistance of a wire carrying 1.5 volts at 0.2 milliamps.

GCSE students must know:

* that I means current. * that milli means one-thousandth; * the relationship V = I x R ;. * how to rearrange the equation to find R, so that R = VI; R = 1.5 (0.21000) = 7500 ohms. Some will worry about the order of the calculation and some may divide 1.5 by 0.2 and divide the answer by 1,000. Can they use their calculator properly?

They might be unfamiliar with resistance and so would find it difficult to check if the answer is sensible. But even with similar calculations for speed they might not know instinctively if a car travelling at 100 miles per second is realistic, whereas a speed of 25mph for a bicycle might prompt them to check their maths.

For such students, working in the classroom becomes as difficult as visiting a foreign country with limited language skills. Unless mathematical skills and concepts are practised and used frequently in a scientific context, they are all too soon forgotten. Students seem to find the ideas difficult to revisit.

So what maths support do schools provide for science students?

Usually what help there is comes from science teachers or, as in my school, a concerned maths department. We have developed software for independent learning of concepts crucial to A-level physics such as speed, acceleration and vectors.

Science students might lose their fear of using maths if maths teachers made greater use of scientific contexts.

Some of the most successful science syllabuses and most popular courses (including Salters' A-level Chemistry and Salters' Horner Physics) put science in a real context. The conceptual ideas are still not always easy, but students seem to latch onto them much faster.

Be creative: at key stage 4 "mole calculations for a reaction yield" feel tedious and dry for the average 15-year-old. But if you set it up in the form "You are the manager of a large industrial ammonia production plant. Your chief engineer wants to know how much sulphuric acid to buy to meet an order for . . .", then suddenly pupils' imaginations are fired and they may just understand the problem.

* John Dexter is head of sixth form at Trinity School, Nottingham *

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