Saturday, March 20, 2010

Algebra Puzzle (3 x 4)

First, we take the present as p, drum as d, and the pumpkin as u.
Refer to the third column:

p + p + p = 33


p = 33 ÷ 3 = 11

Now we refer to the first row:

70 = p + d + p + d
=11 + 11 + d + d
=22 + d + d


70 - 22 = d + d
48 = d + d
d = 48 ÷ 2
d = 24

Finally, we refer to the last column:

66 = d + u + d
66 = 24 + 24 + u


66 - 24 - 24 = u
18 = u

So the answer is: Present = 11
Drum = 24
Pumpkin = 18

Friday, March 19, 2010

Algebra Puzzle (3 x 3)

First, we take the ice-cream as c.
The flower as w, and the gear as g.

15 = c + c + c
= 3c
c = 15 ÷ 3
= 5

Now that we know c = 5, the next step(3rd row) is:

35 = c + g + g
= 5 + g + g


35 - 5 = g + g
30 = g + g
30 ÷ 2 = g
15 = g

Finally, we can evaluate(the 1st row):

c + w + g
=5 + 15 +w
=20 + w


w = 23 - 20
= 3

So the answer is: Flower = 3
Gear = 15
Ice - cream = 5

Sunday, January 24, 2010

Prime Factorisation (continues...)

Q1.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.)

2^4 X 3^5 X 7^2 X 11= 2 095 632

(a)2^4 X 7^2=784
(b)3^5 X 11=2 673
(c)7^2 X 11=539

Q2.Textbook p9 #26:
The Prime factorisation of two numbers are 2 X 3^2 X 7^3 X 13 and 3 X 7^2 X 13^3 X 17 .
Write down 3 common factors of the numbers.

2 X 3^2 X 7^3 X 13=80 262
3 X 7^2 X 13^3 X 17=5 490 303

and I'm stuck here...

Prime Numbers:Textbook p8 #24

I agree with the claim. An even number can never be a prime number as all even numbers are divisible by 2. So prime numbers are always odd numbers(not assuming all odd numbers are primes, eg.9. But instead of 9+9=18, we can have 5+5+5+3+18). So, when we add up 2 similar odd numbers(or 4 or 6 or 8, etc.), the resulting answer will be an even number(adding 2 similar numbers is like multiplying the number by 2, which will result in an even number). That is why every even number greater than 2 can be expressed as a sum of prime numbers.

Wednesday, January 13, 2010

12 January: Numbers as a Language

I think the Mayan numerals are easy to remember. They are basically just dots and lines. For example, the number "0" is shaped like and oval with a curved line drawn across it. It is actually a picture of a shell. The number "1" is just a dot, and number "2" is 2 dots. And it goes on all the way till 5, where it is a horizontal line. but this is just the basics...

Just as we have place values like tens, hundreds and so on, the Mayans also have what is like our place values. But theirs is according to the number "1", number "20", and the number "400". For example, 35 would be written as one dot above five dots, which are in turn atop two lines.
The first dot represents "one twenty" or "1×20", which is added to five dots and two bars, or thirteen. Now that's simple enough.

Tuesday, January 12, 2010


Communication is important because we may have to convey messages from one another in this fast-paced society of ours. if we cannot even express ourselves to other people, how can we make them appreciate what we are trying to do? Without communication, the world would be like a ghost town, with everyone living in solitude. That is why communication is so important.

Of course, there are various forms of communication we can choose from. But my personal favorite is by email. Emails are usually free of charge, and messages travel very fast across the globe. The recipient would probably receive the message 2 seconds after it is sent, compared to sending letters by post as it would take 2 weeks.

To deal with different situations, different forms of communication is required. For instant, if it is someone overseas whom you want to communicate with, the email is preferred over a call on the telephone as overseas phone calls can be very expensive, especially if they are used frequently.

Some difficulties I face when communicating with others is that I think people do not know what I am trying to say, perhaps because I speak in Singlish most of the time and I always do not seem to be serious. But I think I should speak more proper English so I would be easier to understand.

Wednesday, January 6, 2010

The Amazing Race

Hi again! I feel that the meaning of expanding learning network is trying to learn more, like today at The Amazing Race. We were kind of lost at the end of the race. We all had no idea of how to get to Blk 310, Clementi. and everyone were arguing like cats and dogs. No one even "expanded their learning network by asking for help from passers-by, which was a big mistake and make us come in 4th in the race. And that is a perfect depiction of EXPANDING your learning network.

I feel that this value is important as in SST, we will have to meet a lot of new people, and we have to communicate and learn from them as well. It will benefit me in my learning experience here, in this case.

And that's all for now!