# 4.23 To do mental arithmetic

 Page 1 / 1

## Memorandum

1. 6 × 7 = 42

2. 7 × 9 = 63

3. 6 × 7 = 42

4. 9 × 5 = 45

5. (4 × 12) + 13 = 61

6. (6 × 8 ) + 8 = 56

7. 144 ÷ 12 ÷ 6 = 2

8. 2 001 – 17 = 1 984

9. 72 ÷ 8 = 9

10. 24 ÷ 3 = 8

11. 132 ÷ 11 = 12

12. 3 × 3 × 3 = 27

13. 96 ÷ 12 = 8

14. ( 30 ÷ 6) × 4 = 20

15. 13 × 4 × 8 × 0 = 0

TEST

1.

1.1 straight angle

1.2 obtuse angle

1.3 acute angle

2.

• 40º
• 150º

3.

3.1 No

3.2 Yes

4. 8 ; 8 ; 6

5. The ages of ten teachers are as follows:

23 ; 23 ; 29 ; 35 ; 41 ; 42 ; 42 ; 42 ; 47 , 53

5.1 42

5.2 41 / 42

5.3 37 ,7

6. Total number of times it took place

Total number of posibilities

7.

7.1 $\frac{7}{\text{17}}$

7.2 $\frac{7}{\text{27}}$

## Activity: to do mental arithmetic [lo 1.9]

Let's round off the year's work with our last mental arithmetic test. Test your skill by answering the following questions as quickly and correctly as possible:

1. 6 × 7 = _____________________

2. 7 × 9 =_____________________

3. 6 × _____________________ = 42

4. _____________________ × 5 = 45

5. (4 × 12) + 13 = _____________________

6. (6 × _____________________) + 8 = 56

7. _____________________ ÷ 12 ÷ 6 = 2

8. 2 001 – 17 = _____________________

9. 72 ÷ _____________________ = 9

10. _____________________ ÷ 3 = 8

11. 132 ÷ 11 = _____________________

12. 3 × 3 × 3 = _____________________

13. 96 ÷ _____________________ = 8

14. (_____________________ ÷ 6) × 4 = 20

15. 13 × 4 × 8 × _____________________ = 0

TEST

1. What kind of angles are the following?

 1.1 1.2 ___________________________________ ______________________________ 1.3 ___________________________________ ______________________________

(3)

2. Measure the following angles with your protractor:

 2.1 2.2 ___________________________________ ______________________________

(2)

3. Do the following figures have rotational symmetry?

 3.1 3.2 ___________________________________ ______________________________

(2)

4. Complete: A cube has _______________ edges; ________________ angular

points and _________________________________ faces.

(3)

5. The ages of ten teachers are as follows:

35 ; 41 ; 23 ; 42 ; 42 ; 53 ; 47 ; 42 ; 23 , 29

5.1 Determine the mode:

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

(1)

5.2 Determine the median:

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

(2)

5.3 Determine the arithmetical average:

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

(3)

6. What “formula” is used to determine possibility?

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

(2)

7.

7.1 What is the probability that I will take a green ball out of a basket with 7 green, 6 red, and 4 yellow balls?

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

(1)

7.2 What is the probability that I will take a yellow Smartie from a container with

5 green, 9 blue, 7 yellow, 2 pink and 4 red Smarties?

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

(1)

## 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.

where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
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
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
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
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?
what is a peer
What is meant by 'nano scale'?
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 ?
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?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
Got questions? Join the online conversation and get instant answers!