Comments on: Numbers – Remember What They Taught You In Primary School? http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school Sassy O Level Maths Tuition, Questions & Tips from Singapore's Favourite Private Tutor Sun, 05 Feb 2012 17:08:39 +0000 hourly 1 By: michelle http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-32127 michelle Mon, 09 Nov 2009 14:06:52 +0000 http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-32127 hi i dun understand 1234 can help hi i dun understand 1234 can help

]]> By: MathsRock http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-30743 MathsRock Sun, 11 Oct 2009 08:19:37 +0000 http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-30743 *For no.1, find HCF, which is 2x3 = 6. *For no.2, find LCM, which is 2squarex3squarex5x7 = 1260. *For no.3: The prime factors of 126 is 2x3squarex7. 2 and 7 is not a perfect square, so make 2 and 7 become, 2square and 7square. So just add another 2 and another 7. So k is = 2x7 = 14. *For no.4, if you how to do no.2, you should know how to do this. Simply, 1260 divide by 60 = 21. Correct? (: *For no.1, find HCF, which is 2x3 = 6.
*For no.2, find LCM, which is 2squarex3squarex5x7 = 1260.
*For no.3:
The prime factors of 126 is 2x3squarex7.
2 and 7 is not a perfect square, so make 2 and 7 become, 2square and 7square. So just add another 2 and another 7. So k is = 2x7 = 14.
*For no.4, if you how to do no.2, you should know how to do this.
Simply, 1260 divide by 60 = 21.

Correct? (:

]]> By: Miss Loi http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-2592 Miss Loi Thu, 20 Dec 2007 05:55:13 +0000 http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-2592 Hi Jala, LCM = Lowest Common Multiple. Care to elaborate on which part do you not understand? Hi Jala, LCM = Lowest Common Multiple. Care to elaborate on which part do you not understand?

]]> By: Jala http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-2585 Jala Wed, 19 Dec 2007 17:40:54 +0000 http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-2585 what is the LCM i do not understand... what is the LCM i do not understand...

]]> By: Miss Loi http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-1478 Miss Loi Sun, 14 Oct 2007 16:09:32 +0000 http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-1478 Part 4 is a little tricky, so let's explain this one step at a time. i. 60<var>m</var> is a multiple of 126. But obviously 60<var>m</var> is also a multiple of 60! ii. By this definition, do you agree that when <var>m</var> is at its 'smallest integer value for which 60<var>m</var> is a multiple of 126', this implies that 60<var>m</var> IS the <acronym title="Lowest Common Multiple">LCM</acronym> of both 60 and 126? iii. The <acronym title="Lowest Common Multiple">LCM</acronym> of both 60 and 126 is 2 x 2 x 3 x 3 x 5 x 7 (obtained in part 2). So we can equate: 60<var>m</var> = 2 x 2 x 3 x 3 x 5 x 7 <var>m</var> = (2 x 2 x 3 x 3 x 5 x 7)/(2 x 2 x 3 x 5) ... cancel here ... cancel there ... <var>m</var> = 3 x 7 = 21 Part 4 is a little tricky, so let's explain this one step at a time.

i. 60m is a multiple of 126. But obviously 60m is also a multiple of 60!

ii. By this definition, do you agree that when m is at its 'smallest integer value for which 60m is a multiple of 126', this implies that 60m IS the LCM of both 60 and 126?

iii. The LCM of both 60 and 126 is 2 x 2 x 3 x 3 x 5 x 7 (obtained in part 2). So we can equate:

60m = 2 x 2 x 3 x 3 x 5 x 7
m = (2 x 2 x 3 x 3 x 5 x 7)/(2 x 2 x 3 x 5)

... cancel here ... cancel there ...

m = 3 x 7 = 21

]]> By: Miss Loi http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-1476 Miss Loi Sun, 14 Oct 2007 16:00:05 +0000 http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-1476 Hey Prodigy, Thanks for rekindling this post from the early days, when Miss Loi was just a budding blogger making her first baby steps into the blogging world (and she still is) ... Anyway to explain this better ... First of all do understand that part 1 deals with <acronym title="Highest Common Factor">HCF</acronym> and part 2 deals with <acronym title="Lowest Common Multiple">LCM</acronym>. For part 3, you need to find the least value of <var>k</var> such that 126 x <var>k</var> is a perfect square (i.e. can be square-rooted, if there's such a word :P). For a number to be a perfect square, <em>there must be at least two of each of its factors</em>. Hence for 126 = 2 x 3 x 3 x 7, we need at least another 2 and 7 to 'complete the square' (i.e. make it into 2 x 2 x 3 x 3 x 7 x 7). So <var>k</var> must be 2 x 7 = 14. Hey Prodigy,

Thanks for rekindling this post from the early days, when Miss Loi was just a budding blogger making her first baby steps into the blogging world (and she still is) ...

Anyway to explain this better ...

First of all do understand that part 1 deals with HCF and part 2 deals with LCM.

For part 3, you need to find the least value of k such that 126 x k is a perfect square (i.e. can be square-rooted, if there's such a word :P ).

For a number to be a perfect square, there must be at least two of each of its factors.

Hence for 126 = 2 x 3 x 3 x 7, we need at least another 2 and 7 to 'complete the square' (i.e. make it into 2 x 2 x 3 x 3 x 7 x 7). So k must be 2 x 7 = 14.

]]> By: Prodigy http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-1473 Prodigy Sun, 14 Oct 2007 13:32:53 +0000 http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-1473 Miss Loi, care to explain 3 and 4 to me? thanks. Miss Loi, care to explain 3 and 4 to me? thanks.

]]> By: Miss Loi http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-69 Miss Loi Sun, 29 Apr 2007 12:25:15 +0000 http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-69 yk, actually to Miss Loi the LHS is the more important portion which normally means that the RHS is just a formality *excuses herself for not checking properly* but having said that THIS IS AN UNFORGIVEABLE SLAP-YOUR-HAND WHAT-A-PITY WHAT-A-WASTE HOW-ON-EARTH-COULD THIS HAPPEN CARELESS MISTAKE!!!! yk, actually to Miss Loi the LHS is the more important portion which normally means that the RHS is just a formality *excuses herself for not checking properly* but having said that THIS IS AN UNFORGIVEABLE SLAP-YOUR-HAND WHAT-A-PITY WHAT-A-WASTE HOW-ON-EARTH-COULD THIS HAPPEN CARELESS MISTAKE!!!!

]]> By: yk http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-58 yk Sat, 28 Apr 2007 17:18:55 +0000 http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-58 2 x 7 = 17 ?? Minus mark for wrong answer, but still get working marks. (= 2 x 7 = 17 ??

Minus mark for wrong answer, but still get working marks. (=

]]> By: Miss Loi http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-35 Miss Loi Wed, 18 Apr 2007 02:25:19 +0000 http://www.exampaper.com.sg/questions/e-maths/numbers-remember-what-they-taught-you-in-primary-school#comment-35 Tupolev, Of coz you will feel like sec sch - Miss Loi already mentioned this is a Sec One question! No sweat right? Sigh ... but still many students got this wrong. But then again you're overaged! Bully kechil izit??! BTW thanx for dropping by again :) Tupolev,

Of coz you will feel like sec sch - Miss Loi already mentioned this is a Sec One question!

No sweat right? Sigh ... but still many students got this wrong. But then again you're overaged! Bully kechil izit??!

BTW thanx for dropping by again :)

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