Multiple and Sub-Multiple Units Imagine you are to run a marathon race. Would it not be easier to visualize a distance of 30 kilometers rather than 30 000 meters? Units, such as the kilometer, which are larger than the fundamental unit, in this case, meter, are called multiple units. Now imagine measuring the diameter of a coin. Which would you prefer to say: 5 millimeters or 0.005 meters? You would agree that 5mm is more practical. Units, such as the millimeter, which are smaller than the fundamental unit, are called sub-multiple units. There are several multiple and sub-multiple units which are larger or smaller than the fundamental quantity and are written in terms of powers of 10 with each having a designated prefix. PREFIX SYMBOL VALUE PREFIX SYMBOL VALUE Kilo 𝑘� 103 milli 𝑚� Mega 𝑀� 106 micro 𝜇� Giga 𝐺� 109 nano 𝑛� Tera 𝑇� 1012 Figure 1.3 Multiples and their value 10−3 or 10−9or 1 1000000000 pico 𝑝� 10−12or 1 1000000000000 Figure 1.4: Sub-multiples and their value N.B. The value listed is how much times bigger or smaller the prefix is than the base unit. Converting from the Multiple or Sub-Multiple Unit to the base unit: When converting from multiple or sub-multiple units to the base unit, simply multiply the number to be converted by the value of the multiple or sub-multiple prefixes pg. 1 EXAMPLE 2: Convert 36000 𝜇 m to m ��� micro = 10−6 or 1 1000000 Thus, multiply 36000 by 𝟏 𝟏�𝟎�𝟎�𝟎�𝟎�𝟎�𝟎 1 36000μm = (36000× )m 1000000 = 0.036m ANS: 0.036 metres N.B Multiplying by 1 1000000 is = dividing by 1000000 EXAMPLE 1: Convert 1500km to m kilo = 103or 1000 Thus, multiply 1500 by 𝟏�𝟎�𝟑� or 1000. 1500km = (1500 × 1000)m = 1 500 000 m ANS: 1 500 000 metres pg. 2