Lesson 12 — Activity 1: Length
Completion requirements
Lesson 12 — Activity 1:
Length
The metric system of measurement was created about two hundred years ago by a group of French scientists to simplify measurement.
In the metric system, each of the common kinds of measure — length, mass (weight), and capacity (volume) — has one basic unit of measure!
Image Source: Pixabay
The imperial system, on the other hand, (which uses yards, feet, and inches to measure length) was developed over hundreds of years in the UK, and then the French introduced the metric system in 1799, which soon spread through Europe. However, the USA and a few other countries still prefer feet and inches!
In order to have a standard system or language for communicating measurements around the world, most countries use the metric system. The metric system is sometimes called the SI system, which means "System International" from the French Le Système International d'Unités, or more commonly, Standard International Units.
@wikimedia.org
Canada adopted
the metric system as its official system in 1974. However, the old
system is still in use too! It is easy to be confused by these two
systems, so it is important to understand both and be able
to convert one into the other.
Canada
uses the metric system — most of the time! However, there are still
places and occasions where the imperial system of measurement is used. Take a look at the three examples, below, where we still use the imperial system of measurement in our daily lives.
People often talk about their
height
in feet and inches or their
weight
in pounds.
@pexels.com
Another example is the term two by four
when talking about lumber. That term means that a plank is roughly two
inches thick and four inches wide. This is very important information if you are working in the construction industry.
Image Source: Pixabay
If you are working in a bakery and you are baking a cake, for instance, it matters how you do this. You cannot use both systems of measurement. If you start baking using the imperial measurements (e.g., teaspoons, tablespoons, and cups), you need to finish with these measuring tools or the cake may not work out exactly right!
Image Source: Pixabay
These are some examples of where the imperial system of measurement is still commonly used in Canada!
In this theme, you will learn a lot about both systems. In this first lesson, we will begin by taking a look at the metric system and will look closely at length!
Image Source: Unsplash
We can measure how long things are, or how tall, or how far apart they are. Those are are all examples of length measurements.
These are the most common measurements of length:
millimetre
|
Small units of length are called millimetres. A millimetre is about the thickness of a credit card. This is a very small measurement!
@pexels.com
@unsplash
When we have 10 millimetres, it can be called a centimetre.
1 centimetre = 10 millimetres
A fingernail is about one centimetre wide.
We can use millimetres or centimetres to measure how tall we are or how wide a table is, but to measure the length of football field, it is better to use metres.
A metre is equal to 100 centimetres.
1 metre = 100 centimetres
Metres can be used to measure the length of a house, a football field, or the size of a playground.
Image Source: Pixabay
@pexels.com
A kilometre is equal to 1,000 metres.
When we need to get from one place to another, we measure the distance using kilometres.
The distance from one city to another or how far a plane travels can be measured using kilometres.
The metric system relies on a series of prefixes (such as milli,
centi, deca, kilo, etc.) in different amounts or number of
base
units (such as
metre and gram). Converting between the units is easy with the metric
system, because it is based on 10s.
For example, 10 decimetres make a metre.
Image Source: Pixabay
Think about the length of a metre stick. The metre is the standard of length. You have probably used a metre stick before in school, at work, or at home.
Units smaller than a metre have Latin prefixes:
•Deci– means 10; 10 decimetres make a metre.
•Centi– means 100; 100 centimetres make a metre.
•Milli– means 1,000; 1,000 millimetres make a metre.
-------------------------------------------------------------------------------------------------------------
Units larger than a metre have Greek prefixes:
•Deka– means 10; a dekametre is 10 metres.
•Hecto– means 100; a hectometre is 100 metres.
•Kilo– means 1,000; a kilometre is 1,000 metres.
One of the easiest tools you can use to help you convert from one measure to another is to use the ladder or staircase method. This involves moving the decimal in the number that you are working with one place for every "stair" on the ladder. (The basic unit in the chart below is the metre.)
When working with length at school, at work, at home, or in your community, it is important that you choose the appropriate unit of measure. For example, if someone asked you how far away Calgary was from Edmonton, it would be easier to say that the distance is 295 kilometres, rather than saying 295,000 metres!
Let's practise choosing the appropriate length of measure for various items. For example, if you wanted to measure the length of a barn, which of the following would you choose?
-
millimetres (mm)
- centimetres (cm)
- metres (m)
- kilometres (km)
The most appropriate unit would be metres (m)!
Image Source: Pixabay
What about measuring the distance between Sydney, Australia and Paris, France?
-
millimetres (mm)
- centimetres (cm)
- metres (m)
- kilometres (km)
The most appropriate unit would be kilometres (km)!
What about measuring the
height
of a crate?
-
millimetres (mm)
- centimetres (cm)
- metres (m)
- kilometres (km)
The most appropriate unit would be centimetres (cm)!
Image Source: Pixabay
What about measuring the
width
of a pencil?
-
millimetres (mm)
- centimetres (cm)
- metres (m)
- kilometres (km)
Click on the Play button below to watch a movie about metric measurement.