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Mathematics

Grade 5

Measurement and time

Module 51

Length

In this learning unit we shall be looking at different units used to measure length, as well as at the importance of measuring accurately.

Activity 1:

  • To measure and record [LO 4.5.3]
  • To measure accurately with the appropriate measuring instruments [LO 4.7.3]

1. Let us start right away! How well do you know yourself? Measure the following as accurately as possible (your friend may help you):

1.1 the length of your thumb nail

1.2 the length of your little finger

1.3 the length of your right foot

1.4 the length of your left arm from your shoulder to the tip of your middle finger

1.5 How tall are you?

1.6 How high can you reach when you jump up from the ground?

1.7 How much higher is this than your height?

2. What did you use to measure the above?

3. What other measuring apparatus could we also use to measure length?

Do you still remember?

1 cm = 10 mm

1 m = 100 cm

1 m = 1 000 mm

1 km = 1 000 m

Did you know?

  • One metre is roughly the distance from an adult’s nose to the tip of his middle finger on his stretched out hand.
  • The length of a fingernail is roughly 1 cm.
  • The length of a hand is roughly 10 cm.
  • The space underneath your fingernail is roughly 1 mm.
  • The breadth of a little finger is roughly 10 mm.

4. Work together with a friend and complete the following table.

Measure Estimate Actual Measurement Difference
a) the height of your educator ...................... ....................... .......................
b) the breadth of your classroom ...................... ....................... .......................
c) the height of your desk/table ...................... ....................... .......................
d) the total length of the blackboard in the classroom ...................... ....................... .......................

Activity 2:

To solve problems that include selecting, calculating with and converting standard units [lo 4.6]

1. It is important for us to know which measuring units are used for specific lengths. In order to do that correctly, we must know exactly how long the different measuring units are. Let us see how good you are at this! Choose a suitable unit to measure the following:

1.1 The chest size of Dad’s suit (of clothes) is 102 ____

1.2 The height of my bedroom wall is 4 ____

1.3 The breadth of the stoep of the farmhouse is 2,5 ______

1.4 The thickness of my dictionary is 40 _____

1.5 The distance between Johannesburg and Cape Town is more than 1 000 _____

1.6 The depth of the water in our swimming pool is 1,500 _____

2. Circle the measurement that is the closest to reality:

2.1 Our classroom door is about ____high.

(a) 20 m

(b) 200 mm

(c) 2 km

(d) 2 m

2.2 My foot is about ____long.

(a) 26 cm

(b) 26 mm

(c) 26 km

(d) 26 m

2.3 The distance from Durban to East London is ____

(a) 674 mm

(b) 674 km

(c) 674 m

(d) 674 cm

3. Let us look at the way of writing length in the decimal form:

We already know that 10 mm = 1 cm

Thus: 25 mm = 10 + 10 + 5 mm= 1cm + 1 cm + 5 mm= 2 cm + 5 mm= 2,5 cm of 2 1 2 size 12{ { { size 8{1} } over { size 8{2} } } } {} cm

Complete the table:

Number of mm 10 85 ............ 245 ............ 1 026 ............
Number of cm 1 ............ 4,2 ............ 17,9 ............ 146,3

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Mathematics grade 5. OpenStax CNX. Sep 23, 2009 Download for free at http://cnx.org/content/col10994/1.3
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