Introductory Measurement

Metric Units

Most of the world uses the decimalized metric system which is officially called the "International System of Units". SI units include:

Prefixes used at the beginning of each of these units are shown in the table.

LATIN PREFIXES FOR SMALLER UNITS
nano-1 billionth OR 1/ 1 000 000 000
micro-1 millionth OR 1/ 1 000 000
milli-1 thousandth OR 1/ 1000
centi-1 hundredth OR 1/ 100

GREEK PREFIXES FOR LARGER UNITS
kilo-1 thousand OR 1000
mega-1 million OR 1 000 000
giga-1 billion OR 1 000 000 000

Did You Know That...?

The metre was originally defined as the distance between the North Pole and the Equator divided by ten million. Now it is defined as the distance light travels in a vacuum in 1/ 299 792 458 parts of a second.

Converting Length Units

LENGTH RULES CONVERTING LENGTH UNITS
10 millimetres = 1 centimetre
1000 millimetres = 1 metre
100 centimetres = 1 metre
1000 metres = 1 kilometre
When converting from large unit to a small unit, you multiply.

When converting from a small unit to a large unit, you divide.

Examples One - Converting from Large to Small Units

Q1. 5 km = m
Q2. 3.5 m = cm
Q3. 34.6 cm = mm

Answers:
A1. 5000
A2. 350
A3. 346


Examples Two - Converting from Small to Large Units

Q4. 6500 m = km
Q5. 43.8 cm = m
Q6. 3192 mm = m

Answers:
A4. 6.5
A5. 0.438
A6. 3.192

Questions

Complete these length conversions.

Q1. 64.7 km = m
Q2. 63 m = km
Q3. 0.4 m = cm
Q4. 8.4 mm = cm
Q5. 0.9 km = mm

Answers
A1. 64700
A2. 0.063
A3. 40
A4. 0.84
A5. 900000


What is the Difference between Perimeter, Area and Volume?

PERIMETER
In the word perimeter, "peri" means "around" and "meter" means "measure". Therefore, to find the perimeter is to measure around the boundary of an object. Perimeter is measured in metres. Examples where Perimeter is calculated are the length of:


AREA
Area is the flat or two dimensional size of an object. Area is measured in square metres (m2). Examples include the Area to:


VOLUME
Volume is the solid or space inside or the three-dimensional size of an object. Volume is measured in cubic metres (m3). If gas or liquid is measured, it is called capacity and is measured in litres. Examples where Volume or Capacity is used include the amount of:

Maths Fun - How Far Does Chocolate Travel?

Chocolate Box

When you last ate chocolate, did you consider how far the main ingredients - cocoa, sugar, palm oil and vanilla - have travelled to get to your mouth? Brown Cocoa Solids from the cacao tree are primarily grown in Ivory Coast in Africa; Sugar from sugar cane comes mainly from Brazil; Palm Oil is a major export of Indonesia; and Vanilla (the second most expensive flavouring in the world after saffron) is also predominantly cultivated in Indonesia. Use an atlas to estimate the "food miles" or "food kilometres" that these ingredients travelled from the plants to your mouth.