Measuring tools
Length: ruler
Mass: Scale
Symbols
Length: m (metre)
Mass: g (gram)
Capacity: measuring cup
Angles: protractor
Capacity: L (litre)
Angles: ° (degree)
Conventional units of
linear measurement
km
hm dam
m
dm
cm
mm
Perimeter
Area
The distance around a plane
6 cm
P= 6+6+2+2
2
P= 16 cm
The amount of space inside a 2D shape
6 cm
A=length X width
2
A=l X w
A=6X2 so, A=12cm2
Area of parallelogram:
A= base x height
A=b x h
Area of triangle:
A= base x height
2
Volume
Calculating volume:
Volume = area of base X height
or volume = l x w x h
The space a 3D solid occupies.
Written in cubic units (ex:cm3)
Angles
Right angle
An angle that is exactly 90°
To draw a right angle
Obtuse angle
an angle that measures
more than 90° but less
than 180°
Acute angle
Any angle that is less
than 90°
To measure time
Duration
A minute (min.)
60 seconds
A day
24 hours
A year
To calculate lapsed time
decade=10 years, century= 100
years, millennia=1000 years
An hour (hr.)
60 minutes
A week
7 days
365 days or 366 (leap
year), 52 weeks
Conventional units
Measure
length
Measure
mass
Measure
capacity
Km, m ...
Kg, g, ...
l
Make sure units are the same
Example: from 11:07 to 15:36…
from 11:07 to the next hour: 53 minutes
from 12:00-15:00: 3 hours
from 15:00-15:36: 36 minutes
so, 4 hours and 29 minutes
Non conventional units of
measurement