<< Chapter < Page Chapter >> Page >

Mathematics

Number concept, addition and subtraction

Subtraction

Educator section

Memorandum

2. Subtraction

3.1 8

3.2 28

3.3 47

3.4 40

3.5 340

3.6 3 580

3.7 18 200

3.8 18 050

3.9 10 250

3.10 8 250

3.11 18

3.12 14

3.13 8

3.14 12

3.15 45

3.16 450

3.17 350

  • 25 000

3.19 1 500

3.20 250

Leaner Section

Content

Activity: to be able to do mental arithmetic [lo 1.9]

1. It is often necessary for us to be able to add or subtract quickly. We must always try to find "shortcuts" for mental arithmetic. Can you think of a quick way of subtracting 9 from a number, for instance? (See who in your class has got the most effective method for this!)

2. Now are you ready for action? Subtract 9 from the following numbers. Find the matching answer in the wheel and write the letter that is paired with it in the space below, to show what this learning unit covers!

18 31 22 47 25 34 24 47 43 26 14

  • Write your answer here:

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

  • Do you still recognise these?

In 468 – 231 = 237 we refer to

468 as the minuend

231 as the subtrahend

237 as the difference

Thus: 468 - 231 = 237
minuend subtrahend difference
  • Do you also remember?

The INVERSE (reverse calculation) of subtraction is ADDITION.

If you therefore want to check a subtraction sum, you can add.

3. Let’s practise your skills in mental arithmetic again! Subtract the following as quickly as possible. If you know your place values (refer to Learning Unit 1) it will be child’s play.

2.1 17 – 9 = _________________

2.2 37 – 9 = _________________

2.3 97 – 50 = _________________

2.4 97 – 57 = _________________

2.5 360 – 20 = _________________

2.6 3 600 – 20 = _________________

2.7 18 250 – 50 = _________________

2.8 18 250 – 200 = _________________

2.9 18 250 – 8 000 = _________________

2.10 18 250 – 10 000 = _________________

2.11 _________________ – 9 = 9

2.12 _________________ – 8 = 6

2.13 21 – _________________ = 13

2.14 42 – _________________ = 30

2.15 90 – _________________ = 45

2.16 900 – _________________ = 450

2.17 900 – _________________ = 550

2.18 _________________ – 6 000 = 19 000

2.19 21 500 – _________________ = 20 000

2.20 25 750 – _________________ = 25 500

  • Complete by ticking in the applicable column.
NOT AT ALL ONLY A LITTLE A LOT VERY MUCH
I struggle to subtract quickly and accurately
I struggle to subtract quickly
I struggle to subtract correctly

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 1.9: We know this when the learner performs mental calculations.

Questions & Answers

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
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
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
hi
Loga
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Mathematics grade 5. OpenStax CNX. Sep 23, 2009 Download for free at http://cnx.org/content/col10994/1.3
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Mathematics grade 5' conversation and receive update notifications?

Ask