singaporeolevelmaths

Simple Tips for Better Maths Results!

Ai Ling Ong

How 16 Years Old Calculates Income Tax

During this period of time, a Singapore website is ranked high in the search engines. Do you know which website? With the deadline for filing tax to be on 15 April, many people are flocking to IRAS to do their last minute e-file.

IRAS-Yahoo

For a 15 - 16 years old teenager, he gets transformed into a tax officer (though a really entry level one) where he learns the basic in calculating the income tax.

Let's use the following question as an example,

Income-Tax

Chargeable income = Gross annual income (inclusive other income streams like rental etc) minus reliefs

Mr Tan income is only from his work, so gross annual income

= 3250 x 12 = 39 000

Total reliefts

=3000 + 2000 + 2000 x 2 + 7800 + 600 + 2/100 x 39 000

=18 180

Chargeable Income = 39 000 - 18 180 = 20 820

We can refer to the table of tax rate to calculate the amount of income tax Mr Tan has to pay.

Income-Tax

We choose the one circled in red:

First 20 000: $0

Next 820 (20 820 - 20 000): 3.5/100 x 820 = $28.70

I hope you find this post useful. Leave me your comment on Income Tax. Have you learnt the concept? Do you know it's under the topic of 'Everyday Math'?

E-Math: Parallel Vectors & Collinear

How to tell if 2 vectors are //?

It's easy if you're given a diagram. What if a diagram isn't provided? Then we need to look at relationship between the vectors.

As long as 2 vectors are expressed as scalar multiple of each other, the 2 vectors are //. What exactly do I mean? Look at the following example equations, they are examples of vectors // to each other.

This also means if you're able to establish such relationship between 2 vectors, you can prove that the vectors are // to each other.

parallel-vectors

Very often, question will ask you to explain why A, B and C lie on a straight line. (Look at Example 3)

The term to describe 3 points on the line is known as Collinear.

3 Points to show Collinear

  1. Establish a relationship between the 2 vectors
  2. Conclude that the 2 vectors are // to each other
  3. Common point is present

show-collinear

We can even draw a diagram to represent the two vectors. Since the relationship between the 2 vectors has a negative sign, it means that vectors AB and AC are in opposite direction. Vector AC is also twice of vector AB.

collinear

Do you have other ways to prove 3 points are collinear? I would love to hear from you.

Do you know that if you are asked to prove 2 vectors are //? A similar approach can also be used.

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What Matters Most

Most students should have completed your common tests or in the midst of completion.

How have you performed? Are you happy with your results? Are you upset? Or you don't bother at all?

What matters most is perhaps not what you have scored, but moving forward, what do you do with the outcome?

Every test or examination has a lesson for us to learn. Do you sit down and think through the lessons taught or you simply forget about it?

3 Questions to learn the lesson well:

  1. Ask yourself, what are some of the good things you have done? (You start preparation early, you clarify all your questions before the test, you did your assignments consistently, you manage your time well, you handle the questions with calm and confidence)
  2. What did not go right this time? (Slept too late the night before your test, you didn't put in any effort, your 'what's-the-great-deal' attitude, you didn't finish the questions due to poor time planning)
  3. What is one action you would work on to improve upon on your next test or examination?

Regardless how you have fared for your test, there are definitely good things you have done, it just takes time to realize and acknowledge.

So, what you have learnt?

Photo Credit: KaCey97007

2010 GCE 'O' Level Examinations Timetable

I was looking at this year 'O' level examinations timetable and observed the following:

Unlike last year where first official week is reserved for English, E-Math & A-Math, we see a 'scary' schedule in which A-Math Paper 2 is combined with Pure Chemistry Paper 2 or Combine Sci Paper 3 on the same day. (29 Oct 2010)

E-Math Papers are scheduled separately on consecutive days afternoons. This arrangement is just like 2009 timetable. Candidates need to keep themselves in peak performance despite the 230pm paper.

2010 Timetable 29 October

Download the entire 2010 GCE 'O' Level Examinations Timetable here.

For more details, please visit Singapore Examinations Assessment Board. (http://www.seab.gov.sg)