MEASUREMENT
~ finding a number
or value to show the size of amount of something.
Why do we measure ‘things’?
~ to be
able to compare things to each other.
~ to
calculate/gauge
~ cooking
properly with the right amount of ingredient and timing
~ taking
the right amount of medication
~ what
else can you think of? J
UNIT OF MEASURE(UOM)
Units of Measurement provide standards for
what we measure so that the numbers from our measurements refer to the same
thing.
Example:
1 metre is a unit of length.
We say that the unit of measurement is in metre
[We say measure in metre,
and not measure in ‘1 metre’. The ‘1’ is dropped]
LENGTH
~ measurement or extent of something from end to
end.
We can use centimetre(cm), metre, kilometer(km) or millimeter(mm) to measure length.
MEASURING LENGTH
Using cm: The length of the red line is 5cm.
Using metre: Usain won the Gold for the 100m race
100 m is also the same as 10000 cm or 0.1 km or 100000mm.
Using Kilometre: The distance between BuonaVista and Commonwealth is 1.2km
The distance is in km and not 1200m or 120000cm or 1200000mm. Why?
Using millimetre : the length of a grain of rice is about 5mm.
It can also be expressed as 0.5cm, 0.005m or 0.000005 km
COMPARING AND ORDERING LENGTH
Long/Longer/Longest Tall/Taller/Tallest
Short/Shorter/Shortest
Long/tall
short
|
Examples
The black pen is 20cm long.
| |
Comparative
(comparing 2)
|
Longer/
Taller
shorter
|
(blue pen and black pen)
The blue pen is 3 cm longer than the black pen.
-> The blue pen is 20+3 = 23 cm long.
(red pen and black pen)
The red pen is 4 cm shorter than the black pen.
-> The red pen is 20-4 = 16cm long.
|
Superlative
(Comparing 3 of more)
|
Longest/
Tallest
shortest
|
(blue pen, black pen, red pen)
Blue pen is the longest.
Red pen is the shortest.
|
CONVERTING KM/M/CM/MM
1 km = 1000 m
1 m = 100 cm
1 cm = 10 mm
To
convert km to m, multiply the km value by 1000
To
convert m to km, divide the metre value by 1000
Length Converter Formula
“Length” Converter
DIVIDE : <---- Convert direction ----> MULTIPLY
DIVIDE
/ < --- km(1)
: m(1000) : cm(100) : mm(10) --->
x MULTIPLY
Example
Convert 5km to m
Method
Step1 Circle keywords. Draw Converter and locate both conversion units 
Step2 Determine x or /
km to m -> x
Step3 Calculate: Put value at first circle and multiply till second circle
5km = 5 x 1000
= 5000m
Example:= 5000m
Convert 250m to mm
Step1 Circle keywords. Draw Converter and locate both conversion units
Step3 Calculate: Put value at first circle and multiply till second circle
Step2 Determine x or /
m to mm -> x
250m = 250 x 100 x 10
= 250 000 mm
Example:
Convert 1.5 m to km
Step1 Circle keywords. Draw Converter and locate both conversion units
Step2 Determine x or /
m to km -> /
Step3 Calculate: Put value at first circle and / until second circle
1.5 m = 1.5 / 1000
= 0.0015km
= 0.0015km
Example:
Convert 250mm to m
Step1 Circle keywords. Draw Converter and locate both conversion units
Step2 Determine x or /
m to km -> /
Step3 Calculate: Put value at first circle and / until second circle
250mm = 250/100 x 10
= 0.25m
END ~
“It was identified that children had difficulties understanding the concept of starting from a fixed point when dealing with length (O’Keefe and Bobis, 2008).”
