Introduction

SI units are the units used in this course. The SI units used in this quiz are the kilogram (kg), metre (m), and second (m).

SI units have standardised prefixes, which pre-multiply the size of the unit of interest. The purpose of prefixes is to make the notation of large or small measurements less cumbersome.

Multiplier   Prefix Symbol Comment
10-12 0.000000000001 pico p
10-9 0.000000001 nano n
10-6 0.000001 micro µ The symbol is the small Greek letter 'mu'. Sometimes 'u' is used if 'µ' is not available e.g. 100 uF.
10-3  0.001 milli m Not to be confused with 'mega (106)' M.
10-2  0.01 centi c
 Commonly used with length (cm), and sometimes with volume (e.g. a 750 mL bottle may be sized 75 cL).
10-1  0.1 deci d Not commonly used, but sometimes used to describe the kilogram in terms of water: 1 dm3
of water (a cube 0.1 m on the side) has a mass of 1 kg.
100  1  -  - There is no prefix.
102  100 hecto h Not commonly used, except in the area unit hectare (ha), and the atmospheric pressure unit hectopascal (hPa).
103  1000 kilo k The kilogram is the base unit of mass, despite containing a prefix already.
106  1000000 mega
 M
 Not to be confused with 'milli (m)'. Sometimes the 'a' in mega is removed when writing units e.g. megohm.
109  1000000000 giga
 G
1012  1000000000000 tera
 T


Assignment Answers and Commentary

The first part of the assignment requires you to circle the relevant quantity. The answers here will be presented in bold.


# Task
 Comment
1 Circle the biggest
 mega milli micro This question is referring to the size of the prefix multiplier, otherwise it makes little sense: mega is 106, milli is 10-3, and micro is 10-6
2 Circle the smallest
 mega milli micro This question is referring to the size of the prefix multiplier, otherwise it makes little sense: mega is 106, milli is 10-3, and micro is 10-6
3 Circle the base unit
 kilogram gram milligram The kilogram is a special case: the base unit has a prefix.
4 Circle the smallest
 kilogram gram milligram This question is referring to the size of the prefix multiplier, otherwise it makes little sense: 1 mg = 10-3 g = 10-6 kg
5 Circle the base unit
 hour minute second The second is the base unit for time.
6 Circle for 106
 nano mega tera
 mega represents 106
7 Circle for µ
 milli micro nano See table above
8 Circle for 0.001 sec
 microsec millisec nanosec 1 millisec = 10-3 sec = 0.001 sec
9 Circle for 1 metre
 106 micrometre
 10-6 kilometre
 1 µm = 0.000001 m i.e. 1 m = 106 µm. 10-6 km = 10-3 m = 1 mm.
10 Circle the base unit
 centimetre millimetre kilometre This question is not completely clear. Technically, none of these units as presented are base units. However, I have made the 'metre' parts bold as that is the base unit part of these units.

Fill in the missing information

The answers are in bold.

Remember to clearly distinguish between milli (m) and mega (M).

10-12 10-9 10-6 10-3 100 103 106 109 1012
p n µ m Base k M G T
pico nano micro milli - kilo mega giga tera


Last modified: Monday, 11 May 2020, 11:02 AM