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Mathematics

Number concept, addition and subtraction

Subtraction

Educator section

Memorandum

1.1 27 848

1.2 18 121

1.3 254 706

2.1 8 486 – 5 456 = 3 030

84 381 – 54 351 = 30 030

86 488 – 56 455 = 30 033

816 823 – 516 523 = 300 300

814 886 – 514 556 = 300 330

2.2 297 300

3.1 (b) R27 414

3.2 (a) 22 526

(b) 65 778

(c) 668 544

Puzzle

(a) 378 – 111 = 267 – 110 = 157 – 10 = 147

(b) 2 598 – 1 111 = 1 487 – 1 111 = 376 – 110 = 266

(c) 14 210 – 110 = 14 100 – 100 = 14 000

Leaner Section

Content

Activity: to be able to solve problems in context [lo 1.10]

To use strategies to check solutions [lo 1.11]

1.1 __________ = 54 321 – 26 473

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1.2 __________= 63 904 – 45 783

_____________________________________________________________________

_____________________________________________________________________

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1.3 __________= 486 213 – 231 507

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

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2. 2.1 Let's have a race! See if you can beat your partner, but remember to work neatly!

  • Take a good look at each number.
  • Replace the figure 8 with a 5 in each instance.
  • Write the new number right below the earlier one.
  • Then calculate the difference between the 2 numbers and write the answer in the last space.

e.g.

2.2 What is the difference between the biggest and the smallest answer?

_____________________________________________________________________

2.3 Compare your answers with those of your partner.

2.4 Check your answers with the help of a pocket calculator.

3. What follows is still another technique to calculate the difference between two numbers.

3.1 Work in groups of three again. Read the following problems attentively and explain the solutions to one another.

a) Kayla's father buys a brand new Renault Scenic for R147 293 and Wayne's father buys a second-hand car for R69 475. How much more does Kayla’s father pay than Wayne's father?

Kayla's father pays R77 818 more.

b) Roberto frequently has to make overseas phone calls and his telephone account comes to R30 000. Carli uses her cell phone to make telephone calls and her account comes to R2 586. By what amount is Carli's account less than Roberto's account?

Carli pays R27 414 less.

3.2 Calculate the following by making use of the above method:

a) __________= 42 063 – 19 537

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b) __________= 264 136 – 198 358

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c) __________= 900 000 – 231 456

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TIME FOR SELF-ASSESSMENT

We have now studied different techniques / strategies to do and to check calculations. How do YOU feel about the work we have just completed?

Assess yourself by circling the figure in the applicable column.

** COMPLETELY UNCERTAIN SLIGHTLY CERTAIN FAIRLY CERTAIN VERY CERTAIN
I can round off correctly to the nearest 1 000 1 2 3 4
I can subtract by adding 1 2 3 4
I can estimate the difference by means of rounding off 1 2 3 4
I can subtract by rearranging numbers in extended notation 1 2 3 4
I can work with negative numbers 1 2 3 4
I can subtract vertically 1 2 3 4

Puzzle!

You may only use the following keys of your calculator:

1 ; – ; 0 ; =

  • See if you are able to change the first number into the second

number!

e.g. Change 1 416 to 285

1 416 – 1 110 = 306 – 11 = 295 – 10 = 285

a) Change 378 into 147

_____________________________________________________________________

b) Change 2 598 into 266

_____________________________________________________________________

c) Change 14 210 into 14 000

_____________________________________________________________________

Assessment

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 1.10: We know this when the learner uses a range of techniques to perform written and mental calculations with whole numbers;

1.10.1 adding and subtracting in columns.

Assessment Standard 1.11: We know this when the learner uses a range of strategies to check solutions and judge the reasonableness of solutions.

Questions & Answers

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
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
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
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 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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