How to Convert Between Metric & Others
- 1). Find the right conversion number. Every imperial measurement (inches, miles, pounds) has a conversion ratio with the corresponding metric unit. When converting inches to centimeters, for example, this number is 2.54. This simply means that an inch is equivalent to 2.54 cm. You can find lists of all conversion numbers online (see Resources).
- 2). Multiply the imperial unit by the conversion number. For instance, if you want to convert inches to centimeters, multiply the number of inches by 2.54. Ten inches would therefore be 25.4 cm. As conversion numbers are generally not neat, rounded numbers, it is best to use a calculator for precise results.
- 3). Choose the correct prefix. If the number you have is in the thousands or millions (or thousandths or millionths) drop the excess zeros and apply the corresponding prefix. For instance, if you are converting miles to the base metric unit for distance, meters, you will want to add the prefix "kilo-" to the beginning. Therefore, rather than saying 20,000 meters, you should say 20 km. Other common prefixes are milli- (thousandths), centi- (hundredths) and deci- (tenths).
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