# 3.2 Decimal fractions in the context of measurement

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## Decimal fractions in the context of measurement

Activity 1:

• To recognise and use decimal fractions in the context of measurement [LO 1.5]
• To estimate, measure, record, compare and order two-dimensional shapes and three-dimensional objects using S.I. units [LO 4.5]
• To estimate, measure, record, compare and order two-dimensional shapes and three-dimensional objects using S.I. units [LO 4.7]

1. Measuring Mass: grams and kilograms: 1 000 g = 1 kg

Hands on: practical work

You may work in pairs or groups for this work. You will need to look at a new box of 100 tea bags and you will need a kitchen scale, one tea bag to work with, a box of cornflakes, a packet of margarine and a brick. You will also need a bathroom scale and a weight-watcher’s scale if possible (so work in a group and each one can bring two items of the above).

1.1 Estimate the mass of the box of tea bags. Pass it around the group. Did some clever person look at the outside of the box? Yes, they have to write the MASS on the outside.

1.2 Now pass the box of cornflakes around.

1. What is its mass? .
2. Which is larger : a box of tea bags or a box of cornflakes? .
3. Which is heavier: a box of tea bags or a box of cornflakes? .
4. Yes, it depends on the size of the box of cornflakes. One can get a box of cornflakes that has the same mass as 100 tea bags.

What would that mass be? .

1.3 Carefully take out one tea bag. Handle it carefully, as it can break easily. Pass it around the group.

a) Estimate the mass of one tea bag. What do you think is its mass, when you

hold it in your hand? .

b) Now discuss in your group: How can you calculate the mass of one tea bag, using the information that you have at present? An adult is not to tell you, please!

Hint: Look at the writing on the box. There’s something there that can help you.

c) Now use the weight watcher’s scale to measure the mass of one tea bag. What is it? (It’s a small mass, and not so easy to read. Maybe your educator

can help you to read it.)

d) Use the kitchen scale to measure the mass of the box of tea bags and the box of cornflakes. Is the writing on the outside of the boxes accurate?

1.4 Now, carefully, pass the brick around. Estimate the mass of the brick. Complete the table, USING “GRAMS” OR “KILOGRAMS” as necessary. Write in “g” or “kg”:

 Object My estimation Actual measured mass 1 Tea bag Margarine Brick ME!

2. Measuring Length and Distance.

Hands on: practical work

You will need a tape measure, a ruler and any other measuring instruments that you can bring (e.g. tape for measuring “Long Jump”. You may work in groups. In each of the following tasks, ESTIMATE the length and write down your estimation BEFORE you actually measure. You may ask a friend to help with the accurate measurement. Write your findings in the table on the next page.

R ecordings:

 Item ESTIMATION Actual Measurement Round my head Round my friend’s head My foot (length) My height (height) A very tall person: My eye-lash (length) My thumb-nail (width) My longest finger (length)

#### Questions & Answers

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
Do somebody tell me a best nano engineering book for beginners?
s. Reply
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
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
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Mueller Reply
Read about ancient clocks like_ hour glass, water clock and sun dial for a quiz and hand on Activity in the class
Neha Reply

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Source:  OpenStax, Mathematics grade 4. OpenStax CNX. Sep 18, 2009 Download for free at http://cnx.org/content/col11101/1.1
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