Science Guide Books

[ezmummy]

Uuuuhhhhh… I see!!!


This kind of questions comparing heartbeat of different activities is quite common. I do agree that it’s very hard to compare between the walking toddler and running boy. Hmmmm…

[G Tan]

There are more than one changed variable in this question which is not allowed in sicenc testing!!

[kitty2]

annamom:

Dear all,


The question is about four children involving in some activities. namely:
a boy running (Tom), a boy sleeping(Jack), a boy doing homework (Peter)and a toddler walking (Matthew).

A graph shows the heart beat of the four and requires to identify the heartbeat rate of the children involving in these activities.

The most suitable available answer is whereby Matthew has the highest heartbeat rate ,followed by Tom, Peter and jack.

The reasoning is: toddler has a higher heartbeat rate than a boy.

The other answers will not qualify because eventhough Tom should have the highest heartbeat as he was running, the only available answer there whereby Tom has the highest heartbeat was in this order : Tom, Matthew,Jack ,Peter which is not right as jack was sleeping so his heartbeat should not be higher than Peter who was doing his homework. (Unless Jack was having a nightmare but we should simplify and leave it that he really is resting and not confuse ourselves further)

Overall I feel that the question requires some level of understanding of the text and prompt us to think deeper. I find the question silly similarly as in I find many other questions silly too. However, questions which I find silly, my son could explain to me otherwise.

Conclusion on my part, yes this question is \"silly\" but think we will be seeing more \"silly\" questions coming our way.

I agreed with you,alot of PSLE questions were also \"silly\" questions or rather commsense questions.

[cimman]

G Tan:

There are more than one changed variable in this question which is not allowed in sicenc testing!!

yes, this is totally unscientific. Not only are the participants in different age group, they are doing different exercises as well.
The author has just thrown the concept of \"fair test\" out of the window.
Better stay away from this book.

Speaking of silly experiments, has anyone wondered about the validity of the common experiment where they have two balloons on a balance beam and one balloon is fully blown while the other is flat ? the one that is fully blown is always shown to weigh more than the flat balloon. Has anyone tried this experiment ? assuming the full balloon is full of air and not carbon dioxide

[plum-cake]

I am glad that different authors for lower blk n upper blk science practice!

[pixiedust]

I am also of the opinion the question is badly set. The child can select the best of the bad answers using reasoning but he will also have to ignore the concept of fair test.


I usually stick to authors who have been writing Science Assessment books for many years eg. Janet Sim.

cimman

I've never tried the experiment. Are you suspecting the blown up balloon will not be on the lower side of the balance (ie. heavier) ? Hmmm......now I am wondering too.

[janet88]

pixiedust:

I am also of the opinion the question is badly set. The child can select the best of the bad answers using reasoning but he will also have to ignore the concept of fair test.


I usually stick to authors who have been writing Science Assessment books for many years eg. Janet Sim.

Although many authors are using Marshall cavendish, we have to be careful which authors to get for science...that question mentioned by G Tan is really misleading...how can such a question be set ? Variables are all wrong to begin with. Subject should be the same and not introduce a toddler.
The answer is :siao: too.

Janet Sim, Renee Chong, Helen Lee and Patricia Chan are more reliable.

[cimman]

pixiedust:

I am also of the opinion the question is badly set. The child can select the best of the bad answers using reasoning but he will also have to ignore the concept of fair test.


I usually stick to authors who have been writing Science Assessment books for many years eg. Janet Sim.

cimman

I've never tried the experiment. Are you suspecting the blown up balloon will not be on the lower side of the balance (ie. heavier) ? Hmmm......now I am wondering too.

I believe both balloons should be the same weight because both are weighed in air. While there is more air inside one of the balloon, air is found both inside and outside the balloon, this will make both of them weigh the same. In essence, we are just weighing the rubber material of the balloon, it does not matter if one balloon contains more air than the other because both are weighed in an environment that is of the same matter that is inside the balloons.

If one balloon weighs more than the other, it is because it contains carbon dioxide ie. blown by a person., which is heavier than air. If balloon is blown by an air pump, we should see a balanced beam.

If one does the experiment in a vacuum, then yes, we should see a difference in weight. However, the balloons would not survive in a vacuum environment, because of the difference in air pressure within and outside the balloon.

[cimman]

after thinking through with a bit more detail on the balance beam question, I find my argument flawed. While air is found both inside and outside the balloons, the density of air is different. Air is more dense in the blown balloon. So there is a difference between the matter inside and outside the balloon.

There is another way to look at this:
for divers, they are used to carrying tanks of compressed air. They will tell you that a tank full of compressed air weighs heavier than an empty tank.

However, I’m not sure if the slight difference in air pressure between the 2 balloons is sufficient to overcome the rotational resistance of the beam balance.

[G Tan]

janet_lee88:

mama diva:

Hi everyone


I desperately need help in searching for good & reliable PSLE Science assessment books for my DS next year 2012.

Also:

Any tips for scoring PSLE Science paper?

Hi mama diva,
Honestly, I'm :imdrowning: too...don't know what to expect next year either. Other than info/advice from parents of kids this year in KSP, I don't have any idea.

I'm presently using this P5/6 Teachers' Circle as revision. What I like is the explanation given for each MCQ as well as the breakdown of marks for answers in open-ended section. The other assessment I'm using is the MCQ published by Just Education (Jesslyn Poh).
A friend of mine recommended this title.
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I saw more and more mistakes in this Book!! so all mummies, pls do not buy this book!!!