# 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

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
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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