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Grade 9


Module 4

How long is a piece of string?


1 Work in a group to answer the following questions:

1.1 How many metres is a thousand millimetres?

1.2 Which units are the best for giving the following quantities? Some are difficult, and you may have to do some research and bring a better answer back later.

1.2.1 How tall you are.

1.2.2 The distance between our sun and the nearest star.

1.2.3 How long it will take to walk from Cape Town to Cairo.

1.2.4 The amount of milk you drink in a year.

1.2.5 The quantity of vitamin C one has to take in daily.

1.2.6 The temperature of a patient in a hospital in New York.

1.2.7 The area of Greenland.

1.2.8 The speed of a car on the open road.

1.2.9 The amount of wood a cabinetmaker orders at one time.

1.2.10 The total amount of money the government collects in taxes in a year.



The passing of time.

  • We use watches and clocks to show how time passes.
  • Do the following questions as a project. Don’t make yourself guilty of plagiarism.

1 Explain the difference between analogue and digital clocks / watches.

2 List all the clocks in your home, and say whether each is analogue or digital.

3 Find at least one other method used to measure time or show the time – one that is not generally used in western culture. It can be something from earlier times, or something from another country. Try to find something about timekeeping in Africa. Explain clearly how it works.

  • The project must be handed in on: ..................................................

end of PROJECT


1 Complete any remaining questions from the class assignment above.

2 What measuring instruments are used for the following measurements?

2.1 How tall you are.

2.2 The mass of a new–born baby.

2.3 The amount of milk you have to add, in a recipe.

2.4 The paint used for painting the outside of an ordinary house.

2.5 Humidity.

2.6 The speed of a moving car.

2.7 We have a very complicated way of determining leap years. Find out:

2.7.1 Why we need to have leap years, and

2.7.2 Which years will be leap years.


Connecting with the world – ASSIGNMENT

  • Choose one of these questions to do.

1 You’ve just discovered your granny’s old recipe book. You remember some of her recipes, and you’d like to try them too. Unfortunately it uses old–fashioned units, which would be a lot of trouble to convert each time. Decide how you can make some kind of aid, like a table of graph or formula, to make conversions easier. The units that occur often are: the temperature of the oven is given in °F; the measures of mass are in ounces and pounds and the liquid measures are in pints.

2 Your father has just bought you a second–hand car, but it was imported from America and all the instruments use units you are unfamiliar with, and have difficulty making sense of. Decide how you can make some kind of aid, like a table or graph or formulae that you can understand exactly what units like miles, gallons, miles per gallon (petrol consumption) mean in our units.

Questions & Answers

what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
im not good at math so would this help me
Rachael Reply
how did I we'll learn this
Noor Reply
f(x)= 2|x+5| find f(-6)
Prince Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
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
what is system testing
what is the application of nanotechnology?
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
anybody can imagine what will be happen after 100 years from now in nano tech world
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
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele 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 9. OpenStax CNX. Sep 14, 2009 Download for free at http://cnx.org/content/col11056/1.1
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