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Educator section


p. 1: When you begin with operations, make the learners aware that the four operations (addition, multiplication, subtraction and division) involve only two different processes:

Two processes Together Separate

This includes concepts like: Add togetherJoinAltogether Take awaySeparateHand out/Divide

Four signs + x _ ¸

differentgroups equalgroups differentgroups equalgroups

Look at schematic representations

+12 + 14 = 35 -26 - 12 = 14

x5 x 3 = 15 ¸30 ¸ 3 = 10

The more the learners see this representation, and hear the explanation, the better they will understand and be able to apply it when solving problems.

The learners must understand the commutative property of addition

(3 + 4 = 7 and 4 + 3 = 7 ) and multiplication ( 2 x 5 = 10 and 5 x 2 = 10 ), but they need not know or use the words “commutative property”.

p. 2: The learners must understand the associative property of subtraction

(9 – 4 = 5 and 9 - 5 = 4 ) and division ( 10 ¸ 2 = 5 and 10 ¸ 5 = 2 ).

p. 3: Learners must first experience with concrete objects how the answers to the subtraction operations can be checked: return what you have taken away and if you have the number you began with, you know your answer is correct. Later this can then be done in writing.

Encourage them to check regularly and later they will do it automatically.

Leaner section


Activity: number sentence [lo 1.9]

  • Bonny has read 3 books and Tommy has read 4 books. Together they have read 7 books.

Number sentence: 3 + 4 = 7

Let’s have Bonny and Tommy change places:

Number sentence: 4 + 3 = 7

  • The numbers on either side of the + sign can change places without the answer changing!
  • Do the same with:
LO 1.9
  • Mom gives Bonny and Tommy 9 apples. Bonny takes 4 apples. There are 5 apples left for Tommy.

Number sentence: 9 - 4 = 5

  • Now let’s give Tommy’s apples first:

Number sentence: 9 - 5 = 4

The numbers on either side of the = sign can change places.

Watch 9 - 4 = 5

carefully! 9 - 5 = 4 Now do the same with:

  • Tommy cannot remember how much money he had in his purse this morning. He knows that he bought fruit for R5 and he now has R3 left. Help him. How much did he have this morning? ____________________________________
LO 1.9
  • Bonny and Tommy want to know if their subtraction number sentences are correct. We can help them to check their sums.

Number sentence: 9 - 4 = 5

Check! Put everything you took away and everything that was left, together again. If you have the same number that you started with, your calculation is correct.

  • Now do the sums and check your answer every time:


Learning Outcome 1: The learner will be able to recognise, describe and represent numbers and their relationships, and to count, estimate, calculate and check with competence and confidence in solving problems.

Assessment Standard 1.9: We know this when the learner performs mental calculations involving:

1.9.1 addition and subtraction for numbers to at least 50;

1.9.2 multiplication of whole numbers with solutions to at least 50.

Questions & Answers

what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
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
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
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.
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
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
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
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
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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.
what is the actual application of fullerenes nowadays?
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.
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 3. OpenStax CNX. Oct 14, 2009 Download for free at http://cnx.org/content/col11128/1.1
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