Friday, 29 March 2013

important algebraic expansion





Data Handling: Choice of graphs by Xue Qin


Task 1: 

1.Can you identify which is the least appropriate?
Line graph is unsuitable for representing the information 

2.Why do you think it's not appropriate?
 I think it’s inappropriate for representing information as line graph* are used when comparing the level or trend of the same thing (for example: The rainfall per month), while 

*A line graph is a type of chart which displays information as a series of data points connected by straight line segments. It is a basic type of chart common. It is similar to a scatter plot except that the measurement points are ordered  and joined with straight line segments. A line chart is often used to visualize a trend in data over intervals of time – a time series – thus the line is often drawn chronologically. 

3. What makes you think that the other graphs are appropriate? 
Pictograms,bar graphs, pie charts can be used to compare different things (for example: The no. students that read a certain genre of books) as well as represent the different level/ degree of a certain data. 





Tuesday, 26 March 2013

Data Handling: line graph {Eunice}




I think a line graph is not appropriate to represent the data above, which is weather. A line graph is normally used to analyze /observe a trend of a certain subject over a period of time. 
eg. A heating and cooling curve. Thus the weather cannot be represent by the line graph.


The other remanding charts are:
bar chart, pie chart, and pictogram. 

A bar chart can represent how many days it is sunny, windy, cloudy etc.
A pie chart can show how many percentage per weather occurred.
A pictogram can show the weather occurring in a very visual form. 
Thus, I think that these three is appropriate, but not the line graph.



Sunday, 24 March 2013

Data Handling: Choice of Graphs by Chua Chester

1. Can you identify the one that is not appropriate? 




2. Why do you think it's not appropriate?

This one above is inappropriate because a line chart is suppose to represent trends over a period of time, not the quantity of items in a situation.




3. What makes you think the 3 remaining graphs are appropriate?


The other graphs provide data that is helpful in finding out the number of areas that have the same weather. 




Data Handling: Choice of Graphs by Qayyum

1.Can you identify which is the least appropriate?

2.Why do you think it's not appropriate?

I think it is because a line graph is more for measuring things that happen over a period of time rather than comparing data.

3. The other three represent the different types of weather individually while the line graph relates them together.

Data Handling: Choice of graphs by Kai Cheng



The line graph is inappropriate as a graph like this represents a situation over time, which is not part of the data.
 The other graphs separate the data of the weather.

Friday, 22 March 2013

Data Handling: Choice of Graphs by Hong Yi


I  think the pie chart is the worst way of representing the data as the data have to be rounded off making it inaccurate. The other charts are better as the data do not need to be rounded off thus achieving greater  precision.

Data Handling: Choice of Graphs by Taufiq

I think it is wrong because the line graph shows a change over time. but this is the weather for the entire are at the same time. yes.

Tuesday, 19 March 2013

Data Handling: Choice of Graphs by Chow Yu Hin


I think the line graph is the most inappropriate as line graphs are usually used to show a change of time. The other three graphs show the data of the weather individually and not merging the data together like the line graph does.

Data Handling: Choice of Graphs by Lynette Tan


  1. Can you identify the one that is not appropriate? 
The Line Graph is inappropriate.
  • Why do you think it's not appropriate?
Line graphs are supposed to show data that changes over a period of time (e.g. a trend). However, the data that was supposed to be represented had nothing to do with time, it was solely about the number of places which are sunny. Thus, I think it's not appropriate.
  • What makes you think the 3 remaining graphs are appropriate?
The 3 remaining graphs show the exact data that's supposed to be represented (the number of places which are sunny). So, the 3 remaining graphs are appropriate.

Monday, 18 March 2013

Data Handling: Choice of Graphs by Ryan Ng

1)


2)Why do you think it's not appropriate?
It is not appropriate as it shows the change in weather not the number of place which have the weather as the data showed in the other graphs.3)What makes you think the 3 remaining graphs are appropriate?
The Bar graph, Pictogram and pie chart shows the number or percentage of the weather around the world.

Data Handling: Choice of Graphs by Khairul


1.Can you identify the one that is not appropriate?
   -The Line graph is inappropriate.
2.Why do you think it's not appropriate?
   -Line graphs present data over a period of time. In this case, there is no need for the data to be presented over a period of time.
3.What makes you think the 3 remaining graphs are appropriate?
   -The other three graphs do not present data over a period of time. 

Sunday, 17 March 2013

Data Handling: Choice of Graphs by Kenric Tan (22)

1. Can you identify the one that is not appropriate? 

 

2. Why do you think it's not appropriate?
This one above is inappropriate as a line chart represents trends over a period of time, not the amount of things in a situation.

3. What makes you think the 3 remaining graphs are appropriate?

The other graphs provide me with figures that are helpful in finding out what I want (how many areas have what type of weather)


Data Handling: Choice of Graphs by Chelsea Seah

1. Can you identify the one that is not appropriate? 



2. Why do you think it's not appropriate?

The line graph is meant to show the trend over intervals of time but in this case, we are trying to find out the number of places that has a certain type of weather. Thus, the line graph is not appropriate for this context.

3. What makes you think the 3 remaining graphs are appropriate?

They show the exact amount which is what we're trying to find out.

Data Handling: Choice of Graphs by Bryan Goh


I think the line graph is inappropriate. A line graph is supposed to show the difference in the numbers at each events. The other three graphs show the exact number in each of the event which is what we want, not the difference between them.

Data Handling: Choice of Graphs by Bryan Lee





In my opinion, I feel that the line graph is wrong because it is not a decrease in the number of countries with windy weathers but instead, it should be 11 countries with sunny weather and 0 countries with windy weather.

Pie charts: The pie chart shows that all countries have sunny weather.
Pictogram: The pictogram shows correctly the number of countries with sunny weather.
Bar Graph: The bar graph indicates that all 11 countries have sunny weather and the height of each bar is according to the number of pictures of the weather on the diagram.

Data Handling: Choice of Graphs by Timothy Teng

I think that the line graph is inappropriate because each line is used to show one type of information over a period of time.
The other three different type of graph is appropriate because they present the different weathers as different data.




Maths Olympiad news

To all Secondary 1 & 2 Student participants in the Math Olympiad training program. Please note that the session on THURSDAY (21st MARCH 2013) will be for FOUR hours. It will commence at 9am and will end at 2pm (including a lunch break). PLEASE REMIND YOUR PARENTS ABOUT THIS AND BRING YOUR OWN LUNCH THAT DAY BECAUSE THE SCHOOL'S CANTEEN WILL BE CLOSED. If your parents have any questions, please get them to email me at jason_ingham@sst.edu.sg Thank you. Jason Ingham

Keeping Stock and March Holiday

Hi S1-04

The March break has just begin! It is important for all to take the well deserved break and as well as to take things into perspective. It has been a term since you have been in SST - kudos to all for doing a great job.
Take time to be with your family and friends - spend time with them.

In addition to that there are several things to accomplish in the March Vacation, and you will find most of the materials in the GoogleSite > Mathematics site

(1) Performance Task - Viva Voce 
  • This is going to constitute to 5% of your overall Summative Assessment results.
  • Refer to GoogleSite > Mathematics site > Performance Tasks (left panel).
  • This is similar to the Viva Voce Practice that we did.
  • You may go through the questions and attempt your choice question on paper first.
  • Try to do the recording after Monday, when I would be able to provide you feedback to your practice so that you can avoid what you should not do.
  • Note the deadline of the task.
(2) Vacation Engagement
You will be learning a sub-topic on your own during the March Vacation - Introduction to Data Handling.
  • Refer to  GoogleSite > Mathematics site > Vacation Engagement
  • It is a revisit of the what you learnt in primary school.
  • You will be using resources mostly from the AceLearning and attempting exercises at the Maths Blog or GoogleForm.
  • There is a set of homework questions from the Maths Workbook.
  • Note the deadline of the task.
(3) Common Test in Term 2 Week 6
The topics are already listed in the GoogleSite, to give you an early head-start (preparation).
You may do the following as practice: 
  • Workbook 1: Revision Test B1
    • Omit Q5, Q6, Q7
  • Workbook 1: Revision Test B2
    • Omit Q2, Q5, Q6, Q7, Q8
(4) Consultation during March Vacation
The various consultation channels remain open during the March Vacation:

  • Email
  • Online Chat
  • Facebook Message


This is how your Maths GoogleSite looks like. Refer to the left panel for the various tasks assigned.




Data Handling: Choice of Graphs by Beverly Heng


I think pie chart is not appropriate as it is rounded off to the nearest whole number. The 3 remaining graphs are appropriate as they are using the actual numbers and not numbers rounded off.

Saturday, 16 March 2013

Data Handling: Choice of Graphs by Sabrina Fernandez

In my opinion, I think the line graph is not appropriate, as line graph is used to show a trend of only one  information or item. In this case, it shows five different weathers. I think the remaining three is appropriate as the pictograms shows the same number of pictures as of the diagram;  the bar graphs, too, shows the exact same results; the pis chart, though was rounded to nearest whole number, is still accurate as it cannot be presented in never ending decimals.

Data Handling: Choice of Graphs by Kimberly(08)

Can you identify the one that is not appropriate?
Line Graph


Why do you think it's not appropriate?
Each line in a line graph is used to show one type of information. However this line graph uses one line to show the 5 different weathers.
What makes you think the 3 remaining graphs are appropriate?
  1. Pictograms: The number of pictures of the weather in the digram is the same as in the pictograms.
  2. Bar graphs: The height of each bar is according to the number of pictures of the weather on the digram.
  3. Pie Chart: They put the information together, although it is estimated, it is still represented in the correct form. 

Data Handling: Choice of Graphs by Myat Noe


I think the line graph is not appropriate because line graphs are usually used to present trends over time. for one specific piece of data. In this graph, there are 5 different weathers, therefore 5 pieces of data so it is inappropriate. 

Data Handling: Choice of graphs (Nehal Janakraj)



I find that pie chart is the one that is not appropriate when presenting this information about weather. All the figures in the pie chart are rounded off to the nearest whole number, therefore, not giving accurate results. I find that the other three is appropriate as it gives accurate results, and does not round off numbers to the nearest whole number. 

Data Handling: Choice of Graphs by Luke



I think that this graph is not appropriate to represent the information as the figures are rounded off to the nearest whole number and the this graph does not tell readers the specific numbers at a glance.I think that the 3 remaining graphs are appropriate as they tell readers the specific numbers at one glance and the numbers are not rounded off.

Friday, 15 March 2013

Data Handling: Choice of Graphs by [Sean Chiu Yan Ming]



This graph is a line graph.

I thought that it was inappropriate to display the info this way as a line graph normally only represents one piece of data and the change in the lines plots the change of data . Using a line graph to represent or show multiple data was inappropriate in my opinion.

Friday, 8 March 2013

Which is bigger? (Eunice and Nehal)

Let’s say n = -3
5n = 5 x n
    = 5 x -3
    = -15
n^2 = n x n
      = -3 x -3
      = 9
In this case, 5n < n^2

Let’s say n = 2
5n = 5 x n
    = 5 x 2
    = 10
n^2 = n x n
      = 2 x 2
      = 4
In this case, 5n > n^2

Let’s say n = 4
5n = 5 x n
    = 5 x 4
    = 20
n^2 = n x n
     = 4 x 4
     = 16
In this case, 5n > n^2


Let’s say n = 5
5n = 5 x n
    = 5 x 5
    = 25
n^2 = n x n
      = 5 x 5
      = 25


Let’s say n = 6
5n = 5 x n
    = 5 x 6
    = 30
n^2 = nxn
      = 6 x 6
      = 36
In this case, 5n < n^2

Let’s say n = 10
5n = 5 x n
    = 5 x 10
    =50
n^2 = n x n
      = 10 x 10
      = 100

In this case, 5n < n^2

Therefore, in conclusion, n does not have a definite value. We cannot determine which is bigger because we do not know the value of n. In certain cases, 5n is bigger, in other cases, 5n is smaller, or both of them are equal. Thus, we cannot tell which is bigger.

Hi (Yu Hin and Khairul)

It depends on the value of n.
If n = 5, 5n = to n2.
If n > 5, 5n < n2.
If n = negative number, n2 > 5n.

It depends...


The answer depends on the value of n. If the value of n is any whole number which is more than 5, n^2
would be more than 5n as it would be from 6n onwards. Lets say if n is four, it would be less as the result would be 4n which less than 5n and if n equal  to 5 the results would be the same as it would be 5n. If n is a negative number, it n times n would be more as negative times negative would be positive and positive times negative would be negative. As five is a positive number five times negative number would be negative number which is less than a positive number.

Which is bigger? (Kimberly Tan, 08)




5n is less than, more than and equals to n^2
However, it depends on the number that n represents.
If n=more than 0, 5n will be more than n^2.
If n=a negative number, 5n will be less than n^2.
If n=0, 5n will be equals to  n^2
 

Which is bigger? (Bryan Goh, Ryan Ng, Chelsea, Xue Qin)








If n is smaller than 5, 5n > n^2
However if n is negative, 5n < n^2.
If n is equals to 5, 5n = n^2
If n is larger than 5, 5n < n^2

Which is bigger? (Lynette)

The answer will always depend on the value of n as 5n can be equal, more or less than n^2

Basically, 5n = 5*n wheres n^2 = n*n.

So, if n=3, 5n will be greater than n^2 as 5n = 5*3 which is 15. However, n^2 is 3*3 which is equal to 9. Therefore, 5n will be > n^2.

However, if n=5: 5n=n^2. This is because 5n= 5*5 which is 25. n^2=5*5 which is also 25.

Lastly, if n=10: 5n < n^2. This is because 5n will be 5*10 which is 50 whereas n^2=10*10 which is 100.

which is bigger? Taufiq

i went through google and searched "what is the value of an awesome n?" the first value i came across was ten. see ten dollar discount? in this case since n equals ten 5n equals 50 whilst n^2 equals 100. therefore in this case 5n<n^2. but that is only when n is qualified awesome. but in typical math if n>5 then 5n<n^2. but if n=5 then 5n=n^2. but if n<5 but n>0 then 5n>n^2. if n is negative then 5n<n^2

Question: Is 5n > or = n^2 [ Sean, Bryan Lee , Kai Cheng , Kenric]

It depends. 
In the situation which both equations are equal , the value of n has to be 5 or 0.
But in the situation that 5n is larger , the value of n has to be smaller than 5 but more than 0.
Finally ,on the other hand , if n^2 is larger , the value of n has to be larger than 5
So in conclusion, because of the fact that we do not know what is the value of n, we cannot conclude anything as it just depends. 

Which is bigger? Qayyum

5n will be bigger than n^2 unless the value of n is more than 5. If the value of n is 5 then both will be equal. If the value of n is less than 5 than 5n will be bigger than n^2.

For example, if the value of n is 6 then 5n will be 30 and n^2 will be 36.
If the value of n is 5 then both values will be 25.
If it is 4 than 5n will be 20 and n^2 will be 16.

Which is bigger? ~Sabrina


Question:  Is 5n  > or =  n^2 ?

My answer: Well, since n is a variable, it can be any number. Let's say n=3. So 5n =15 and 3^2=9. In that case, 5n is in fact larger than n^2. But on the other hand, n can also =5. So 5n=25 and n^2 is also 25. In that case, 5n=n^2. So well, in my opinion, the answer depends on what number n represents.

Which is bigger ?

by Mr Johari

Given the following please post a new post as to whether they are (i) equal  (ii) one greater than the other. Provide a good proof for this (hint: refer to previous activity). Collaborate with the members of the same group as in the ICT activity.

Question:  Is 5n  > or =  n^2 ?

Algebra ... How "X" finds its value

Thursday, 7 March 2013

FOR FUN ... Egyptian Multiplication

How does this work?

ICT Activity (Yu Hin, Qayyum, Khairul)


Compare each of the following pair of expressions. Are they equal? Explain.
a) 2n and 2 + n
     - They are not equal. 2n = 2 x n, not 2 + n.
b) 2n and n²
     - They are not equal. 2n = 2 x n but n² = n x n.
c) 2n + 2 and 2(n+2)
     - They are not equal. 2n + 2 = (2 x n) + 2 but 2(n+2) = 2 x (n + 2)
d) 2n² and (2n)²
     - They are not equal. 2n² = 2 x n² but (2n)² = 2n x 2n.

ICT Activity (Eunice and Nehal)



(a) 2n and 2 + n is not equal as 2n refers to n x 2, but 2 + n basically refers to 2 + n. The answer will not be the same.
(b) 2n and n^2 is not the same as 2n is n x 2 but n^2 is n being squared, meaning n x n.
(c) 2n + 2 and 2(n+2) is not the same as when we evaluate 2(n+2), we will get 2n + 4, which is definitely not the same as 2n + 2.
(d) 2n^2 and (2n)^2 is not equal as the first one can be evaluated as 2n x n, but (2n)^2 can be evaluated as 2n x 2n.

ICT Activity (Chelsea, Xue Qin& Bryan)

 


3a.
2n = 2 x n
2 + n = (2 + n)     
3b.
2n = 2 x n
n^2 = n^2
3c.
2n + 2 = (2n +2)
2(n + 2) = 2n + 4


ICT Activity (Sean, Bryan Lee, Kai Cheng, Kenric)




3a) No. 2n= 2xn but 2+n is not = 2xn.
3b) No. n^2 = nxn but 2n= nx2.
3c) No. 2(n+2)= 2n+4 and this is not equal to 2n+2.
3d) No. 2n^2 = 2(n^2) but (2n)^2 is ^2 of 2n.