Common Mistake (2): Algebraic Fractions

I think fraction is a weaker area for many students. When it comes to algebraic fraction, some students could not apply the arithmetic operation they learned in numeric fraction to algebraic fraction.

I have some examples to show you but I have to re-direct you to http://www.letsdomaths.com/tips/cm2.php because the upload image is not good.

Score high, score low

In any test or examination, some participants score high and some score low. If you believe there are reasons behind everything happen in the universe, then there must be reasons why some score high and some score low. Throughout my years of conducting tuition classes, I found that one of the major factors of scoring low is making mistakes. The easiest way to bring up the score is to avoid making mistakes.

So, my first tip is to know the common mistakes and how to correct them. It is by no mean an easy task because stubborn mistakes come from years of under-supervision since primary school days. But, with determination, everyone can. I have seen many students with low grades advanced to higher scores in a few months. Take Kevin (not his real name) for example, he came to my class with Grade F9 in N(A) Secondary 3 Elementary Mathematics in the middle of Year 2008. He scored B4 in 'N' level E. Maths that year. He carried on to score B3 in 'O' Level E. Maths in Year 2009. He is studying in Polytechnics currently. While in my class, he corrected many mistakes in his workings and that is one very important reason of his improvement. I have to confess that I was pretty upset by his mathematics ability and serious lack in confidence in the subject initially. I admire him very much for his determination and I consider him one of my best students. I wish him all the best.

I cannot put down all mistakes students made that I know of in one posting. Therefore, I shall put them down one after another under the heading "Tips and hints". I would like to urge teachers, tutors and students (not necessary mine) to comment on these postings and suggest to all of us better ways to correct those mistakes. As my knowledge on mistakes that students made is certainly far from exhaustive, your supplements are appreciated. Furthermore, I welcome any discussions that could help students to improve. I sincerely hope that these postings could help some students to have a better performance in their studies.

May all of us make lesser mistakes, not just in study but also in life. Amen, Au Mi Tuo Fo.......

Common mistake (1): sign ("+" and "-")

The image here is the largest I could figured out. For a clearer image, please go to http://www.letsdomaths.com/tips/cm1.php.

Danger - computer virus

My computer is not working since last night. It was attacked by a new, powerful and unknown virus via email. My anti-virus software failed to detect it and said it is safe to open it. The email contains just two lines. "I need your help" or something like that and an url. Since it is safe to open and I am a curious person, I clicked the url link.

The symptom is once I turn off my computer and open it again, it is closed immediately. So, I cannot use my computer at all. I can't even check the damages. And, I do not have a rescue disk. From the url, it is linked to China.

I am currently using my second computer for this posting. I have to fight with my children to decide who should use this second and last one in the evening. Can any expert tell me how to revive my computer?

My GCE Examination

I took my GCE 'O' Level examination in year 1971. Since year 2005, I take it every year. It is a test of my teaching. The GCE 'O' Level and 'N' Level results of my students become my GCE results. I am just as nervous as my students when the results are out. It took me two days to gather my GCE results from the students or their parents. It is listed in http://www.letsdomaths.com/tips/results2009.php. Three students are not contactable. Their results will be listed once I locate them.

Starting Point

I am afraid to start a blog. I may not have the stamina to continue; or may not able to subject myself to critiques; or may feel shy to expose my bad writings to the world.


I am a part-time private tutor conducting classes in a Tuition Centre. I have students from various walks of life in my mathematics tuition classes. Most of them come from the so-called heartland and study in neighbourhood schools. About half of my students attend 'N' Level course. There are many interesting things I want to record somewhere. So, I am here.

The purpose of this blog is to record mainly my teaching of mathematics; tips and hints given; interesting people I met (not just students and no real names, of cause) and my views on certain issues relating to education. Tips and hints can also be found in my webpage www.letsdomaths.com/tips.php.


Comments, suggestions, encouragements and appropriate criticism are most welcome.