You have two choices, either you think in non-metric units and have to convert metric to non-metric, or learn to think in metric so that you can understand metric units right away; e.g. if someone says they live 5 kilometres away, then rather than convert that to another unit, just think of how far 5 kilometres actually is.
To think metric you have to start using it and relating it to everyday life. It is not enough to just know the names and sizes of the units, you have to actually use them to understand them, such as knowing how big 1 centimetre is, how long a metre is or how far away 150 metres is. One way to start is to stop thinking in non-metric units and try to visualise metric quantities of items, distances, temperatures, volumes, etc. When you resist any temptation to convert a metric unit to a non-metric one, then the familiarity of using metric will soon get you to understand metric. When you see road signs (like the one pictured here on the right) showing a distance in metres, this can help you get used to how long the distance is. In this case, stand at the sign, look towards the Post Office, and see how far that distance is visually, and remember that the distance is 150 metres.
The metric system avoids confusing dual-use of terms, such as the imperial system's use of ounces to measure both weight and volume. The metric system also avoids the use of multiple units for the same quantity; for instance, the imperial system's multiple units for volume include teaspoons, tablespoons, fluid ounces, cups, pints, quarts, and gallons, and the value of these units varies from one country to another. The metric system is the same the world over.
A population that is highly skilled in maths and science is essential for national economic and social progress. By using only the metric system, education and training in these key subjects is much more efficient. A workforce that is truly able to think and "speak" the metric measurement language will be better able to excel in the global marketplace. When you convert your thinking to metric, you are coming into line with the majority of the world who now regularly use metric every day and for every purpose.
If you are in business, such as running a factory, shop or restaurant, it is not difficult to change over to metric, if you have not done so already. UK law already requires pricing to consumers to be in metric (e.g. loose food priced in pence per kilogram) and so businesses need metric measuring equipment, such as scales, rulers, tape measures. If you take the order and price in metric, but measure in non-metric using conversion tables, just think of the time and effort you could save if you change your thinking to metric and just use metric throughout. Customers soon get used to metric if you are using metric, and can more easily ask for metric quantities if they see the shop or business owner/workers using metric.
If you are measuring temperature, convert your thinking to remember that 0 °C is freezing and 100 °C is boiling. Normal body temperature is 36.8 °C. Get used to thinking in terms of Celsius rather than trying to convert it to another system.
Remember that the metric system is EASY! Calculations involve multiples of 10 (rather than 3 or 12) and there are links between units, such as weights and volumes (a litre of water weighs exactly one kilogram, for example).
A great place to learn metric is the supermarket — all groceries these days are marked in metric, all you have to do is start paying attention to the metric sizes, e.g. 1 litre of water, 1 kg of rice. We know it is hard for some people to change something as basic about the way they live as this, but in the long run it is in you and your children's best interests that he or she grow up "thinking" metric. Many good jobs will depend on this in the future, while no position in the 21st century is going to require the use of inches or pounds!