Comments for Mr. Lai's Math Blog http://elai.edublogs.org student tutorials on math contest questions Thu, 15 Jan 2009 04:35:24 -0500 http://wordpress.org/?v=2.8.2 hourly 1 Comment on 2000 Question #25 (by Andrea E., Chris G., Keisha L., Tendy S.) by Esther Tung http://elai.edublogs.org/2008/10/07/2000-question-25-by-andrea-e-chris-g-keisha-l-tendy-s/comment-page-1/#comment-107 Esther Tung Thu, 15 Jan 2009 04:35:24 +0000 http://elai.edublogs.org/?p=21#comment-107 The diagrams in this are actually really confusing. Thy are for making the problem easier to understand, but understanding a diagram labeled A-Z is quite difficult in itself. Maybe doing that slower or in a different way would help. =) ---just a thought. Also, the volume of a... tetrahedron. First of all, what's a tetrahedron and second of all, where do all the numbers come from? Is it a formula for calculating tetrahedrons, or...? Je ne comprend pas... but good job for solving it. The diagrams in this are actually really confusing. Thy are for making the problem easier to understand, but understanding a diagram labeled A-Z is quite difficult in itself. Maybe doing that slower or in a different way would help. =) —just a thought.

Also, the volume of a… tetrahedron. First of all, what’s a tetrahedron and second of all, where do all the numbers come from? Is it a formula for calculating tetrahedrons, or…? Je ne comprend pas… but good job for solving it.

]]> Comment on 2007 Question #22 (by Andros C., Henry F., Valerie L., Annie W.) by Chris Green http://elai.edublogs.org/2008/10/15/2007-question-22-by-andros-c-henry-f-valerie-l-annie-w/comment-page-1/#comment-106 Chris Green Tue, 04 Nov 2008 02:03:06 +0000 http://elai.edublogs.org/?p=49#comment-106 I agree with eric, it's not clear where 1.75 over root 2 came from. Also, please let me know if i'm mistaken but i beleive it should be 0.875 over root 2 (one half of 1.75, one quarter of 3.5), not 1.75, over root 2. I agree with eric, it’s not clear where 1.75 over root 2 came from. Also, please let me know if i’m mistaken but i beleive it should be 0.875 over root 2 (one half of 1.75, one quarter of 3.5), not 1.75, over root 2.

]]> Comment on 2006 Question #24 (by Ian C.) by Jimmy Lou http://elai.edublogs.org/2008/10/15/2006-question-24-by-ian-c/comment-page-1/#comment-105 Jimmy Lou Tue, 04 Nov 2008 01:55:43 +0000 http://elai.edublogs.org/?p=36#comment-105 I know the question is to find the smallest value but you still haven't answered my question of making "the fractions all have common denominators" give you the smallest value . My question was "why do you make all have common denominators to get rid of the fractions to find the smallest value of a+b" and you answered "you find the smallest value by getting rid of the fraction." Do you see the problem in this answer...? I know the question is to find the smallest value but you still haven’t answered my question of making “the fractions all have common denominators” give you the smallest value . My question was “why do you make all have common denominators to get rid of the fractions to find the smallest value of a+b” and you answered “you find the smallest value by getting rid of the fraction.” Do you see the problem in this answer…?

]]> Comment on 2005 Question #23 (by Anne L., Kristy Y.) by James Anderson http://elai.edublogs.org/2008/10/09/2005-question-23-by-anne-l-kristy-y/comment-page-1/#comment-104 James Anderson Mon, 03 Nov 2008 17:51:12 +0000 http://elai.edublogs.org/?p=24#comment-104 Like Esther said, the equation (1/2*6*4^2) was a bit strange. I think a bit more explanation was needed. It took me a bit to figure out that you were really doing. The same thing with the calculations in step 4 (calculating the area of one of the equilateral triangles). The numbers just seemed to float into the video, without any explanation of how they got there or what they were used for. The diagrams helped in showing the [special] triangles you used in calculating the answer, which was nice. However, further clarification would have made understanding the solution quite a bit easier. Like Esther said, the equation (1/2*6*4^2) was a bit strange. I think a bit more explanation was needed. It took me a bit to figure out that you were really doing.

The same thing with the calculations in step 4 (calculating the area of one of the equilateral triangles). The numbers just seemed to float into the video, without any explanation of how they got there or what they were used for.

The diagrams helped in showing the [special] triangles you used in calculating the answer, which was nice. However, further clarification would have made understanding the solution quite a bit easier.

]]> Comment on 2006 Question #24 (by Ian C.) by Ian Carlson http://elai.edublogs.org/2008/10/15/2006-question-24-by-ian-c/comment-page-1/#comment-103 Ian Carlson Mon, 03 Nov 2008 17:38:26 +0000 http://elai.edublogs.org/?p=36#comment-103 Jimmy the question is to find the smallest value of a+b and to do that you need to get rid of the fractions Susan it is okay because "a" has to be a multiple of 11 Jimmy the question is to find the smallest value of a+b and to do that you need to get rid of the fractions

Susan it is okay because “a” has to be a multiple of 11

]]> Comment on 2007 Question #22 (by Andros C., Henry F., Valerie L., Annie W.) by Ramsha Noor http://elai.edublogs.org/2008/10/15/2007-question-22-by-andros-c-henry-f-valerie-l-annie-w/comment-page-1/#comment-102 Ramsha Noor Mon, 03 Nov 2008 08:01:03 +0000 http://elai.edublogs.org/?p=49#comment-102 you lost me after the x= d/√2.. you guys should have drawn mini triangles to explain how you got your equations for x, y, and z. is that still special triangles at work? otherwise, i would just recommend have going slower with the steps, since you cant pause using jing. good stuff otherwise though. you lost me after the x= d/√2..
you guys should have drawn mini triangles to explain how you got your equations for x, y, and z. is that still special triangles at work?
otherwise, i would just recommend have going slower with the steps, since you cant pause using jing.
good stuff otherwise though.

]]> Comment on 2004 Question #23 (by Jerry C., Ricky C., Andy C., Jeff C.) by Chris Choi http://elai.edublogs.org/2008/10/15/2004-question-23-by-jerry-c-ricky-c-andy-c-jeff-c/comment-page-1/#comment-101 Chris Choi Mon, 03 Nov 2008 07:24:07 +0000 http://elai.edublogs.org/?p=43#comment-101 elai Says: October 23rd, 2008 at 11:11 pm Chris. What SPECIFICALLY did the diagrams helped to clarify? The diagrams helped to show that they used ratios to find the other side lengths of the similar triangles. -For example, i liked how you guys rotated and showed RBP and PCS had 2 of the same angles (both had a 90 degree angle, and both had another same angle because it was an isosceles triangle) which proved that it was a similar triangle. - i also liked how u guys kept the numbers on the diagram and continuosly adding more information on the diagram as you go so that we wouldnt forget. - how u flipped and rotated the triangles also helped make this problem alot easier to understand. elai Says:
October 23rd, 2008 at 11:11 pm
Chris. What SPECIFICALLY did the diagrams helped to clarify?

The diagrams helped to show that they used ratios to find the other side lengths of the similar triangles.
-For example, i liked how you guys rotated and showed RBP and PCS had 2 of the same angles (both had a 90 degree angle, and both had another same angle because it was an isosceles triangle) which proved that it was a similar triangle.
- i also liked how u guys kept the numbers on the diagram and continuosly adding more information on the diagram as you go so that we wouldnt forget.
- how u flipped and rotated the triangles also helped make this problem alot easier to understand.

]]> Comment on 2004 Question #23 (by Jerry C., Ricky C., Andy C., Jeff C.) by Andros Chien http://elai.edublogs.org/2008/10/15/2004-question-23-by-jerry-c-ricky-c-andy-c-jeff-c/comment-page-1/#comment-100 Andros Chien Mon, 03 Nov 2008 07:12:18 +0000 http://elai.edublogs.org/?p=43#comment-100 It was explained in a clear voice but I was stuck on one part for a tiny little bit. At first I was confused on what <Q was. You should explain what it is first before saying it. It was explained in a clear voice but I was stuck on one part for a tiny little bit.
At first I was confused on what <Q was.
You should explain what it is first before saying it.

]]> Comment on 2001 Question #23 (by Chris C., Jimmy L.) by Jimmy Lou http://elai.edublogs.org/2008/10/20/2001-question-23-by-chris-c-jimmy-l/comment-page-1/#comment-99 Jimmy Lou Mon, 03 Nov 2008 06:42:56 +0000 http://elai.edublogs.org/?p=69#comment-99 Thanks for the comment, For the first question, we know that k = n because n is the number representing the sequence and k is also the number representing the sequence. For your second question, I believe if you read the question again you will see "...where p,q,r are constants...." That tells you automatically that p,q,r are constants. Thanks for the comment,
For the first question, we know that k = n because n is the number representing the sequence and k is also the number representing the sequence.
For your second question, I believe if you read the question again you will see “…where p,q,r are constants….” That tells you automatically that p,q,r are constants.

]]> Comment on 2006 Question #24 (by Ian C.) by Ricky Chang http://elai.edublogs.org/2008/10/15/2006-question-24-by-ian-c/comment-page-1/#comment-98 Ricky Chang Mon, 03 Nov 2008 06:34:16 +0000 http://elai.edublogs.org/?p=36#comment-98 Nice smooth video, but i have some issues with the question. During the question you didn't mention that a & b are both integer therefore i can't assume that a=11A. You should explain why 6A can`t be 0 eventhough 0 is a multiple of 6. The overall presentation was good and i understood how you got the answer. Nice smooth video, but i have some issues with the question. During the question you didn’t mention that a & b are both integer
therefore i can’t assume that a=11A. You should explain why 6A can`t be 0 eventhough 0 is a multiple of 6. The overall presentation was good and i understood how you got the answer.

]]>