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22 Jan (01): Prime Factorisation (continues...)

Textbook p9 #25:

The Prime factorisation of a number is 2^4 X 3^5 X 7^2 X 11.

Write down 3 factors of the number that are greater than 100.

(Hint: 16 X 11 = 176, which is a factor.)

The number=2x2x2x2x3x3x3x3x3x7x7x11

=2095632

Factors greater than hundred:

2095632/2=1047816

2095632/3=698544

2095632/4=523908

Since all these factors are greater than 100, they are the answers.

Textbook p9 #26:

The Prime factorisation of two numbers are 2 X 3^2 X 7^3 X 13 and3 X 7^2 X 13^3 X 17 .

Write down 3 common factors of the numbers.

1st number=2x3x3x7x7x7x13

=80262

2nd number=3x7x7x13x13x13x7

=2260713

Common factors: 3,7,13

Maths Homework

How do you know if a number is divisible by:

2

3

4

5

9

10

11

2: If the number ends with a 0, 2, 4, 6 or 8, the number is divisible by 2.

3: If all the digits in the number add up to be a multiple of 3, the number is divisible by 3.

4: Every alternate multiple of 2 is divisible by 4.

5: If the number ends with 0 or 5, the number is divisible by 5.

9: Any number divisible by 3 can be divided by 9.

10: If a number ends with a 0, the number is divisible by 10.

11: If a two digit number has two similar digits (e.g. 22, 55), it divisible by 11.

A mathematician proposed that "Every even number greater than 2 can be expressed as a sum of two prime numbers." Do you agree? Why?

Yes, I agree.

Goldbach's conjecture is one of the oldest unsolved problems in number theory and in all of mathematics. It states:

Every even integer greater than 2 is a Goldbach number, a number that can be expressed as the sum of two primes.

The number of ways an even number can be represented as the sum of two primes^[2]

Expressing a given even number as a sum of two primes is called a Goldbach partition of the number. For example,

4 = 2 + 2

6 = 3 + 3

8 = 3 + 5

10 = 7 + 3 = 5 + 5

12 = 5 + 7

14 = 3 + 11 = 7 + 7

From http://en.wikipedia.org/wiki/Goldbach's_conjecture

Communication

1 Why is communication important?
It is important as it allows us to understand how our friends feel and what is their point of view about certain topics, allowing us to foster good relationships with friends and classmates.


2 What is/are your favourite form/s of communication? Why?
I enjoy communicating with people through the phone or through email the most as it is a form of two-way communication and I can 
know their replies so we can prevent arguments and disagreement.

3 How do you decide which form of communication to use in a situation?
It depends on what I need to discuss with them or how much I want to see them. For example, if I only need to discuss about a project, I would use either online chat or speaking to them over the phone. However, if it was a friend I have not met for a long time, I would either use video chat or going out to meet him/her.


4 What difficulties do you face in communicating with others?
When I do not know the person very well or if it was the first time I was meeting him/her, I will have problems trying to speak to them, especially if it is a group of people.


Communication

1 Why is communication important?

It is important as it allows us to understand how our friends feel and what is their point of view about certain topics, allowing us to foster good relationships with friends and classmates.


2 What is/are your favourite form/s of communication? Why?

I enjoy communicating with people through the phone or through email the most as it is a form of two-way communication and I can 
know their replies so we can prevent arguments and disagreement.

3 How do you decide which form of communication to use in a situation?

It depends on what I need to discuss with them or how much I want to see them. For example, if I only need to discuss about a project, I would use either online chat or speaking to them over the phone. However, if it was a friend I have not met for a long time, I would either use video chat or going out to meet him/her.


4 What difficulties do you face in communicating with others?

When I do not know the person very well or if it was the first time I was meeting him/her, I will have problems trying to speak to them, especially if it is a group of people.


12 January: Numbers As A Language

I choose the Roman number system as it is very simple to understand once you get the hang of it. It also has several uses, such as being used in the periodic table and in the Music Theory exams.

In short, it is very useful and it is also easy to remember.

That is why I choose the Roman number system to represent the 2010 number system.

Picture from adrianbruce.com

Adventure Camp In Sarimbun Scout Camp (Reflection)

My objectives:

1. To know my classmates better

2. To participate more in activities during the camp

3. To overcome my fears during the activities

What are the three main points (or more) that I had learnt from all the activities?

I learnt to strengthen the bonds between me and my classmates, and that without teamwork we would not be able to complete the activities and succeed in getting first place in one of the activities involving a lot of cooperation. I also learnt to give respect to my classmates by listening to their ideas more during the discussion time.

How can all these pointers be of help to me?

They can allow me to interact with my classmates more freely and with a better understanding of their interests and preferences. I will also be able to accept their ideas more easily and be more willing to share my own ideas. As a class, we will also be able to work better together.

If I were to have another chance to try all the activities, which one will I choose? Why?

I would choose abseiling as I found it the most thrilling and exciting of all the activities, and I could learn to overcome my fear of heights.

If there is one thing I would like to change about myself, what would that be?

I would still participate more in the discussions and activities, as well as to try harder in all the activities and games. It would also be good to get to know more of my classmates better.