## Thursday, 31 July 2014

### Interior angle & Exterior angle - They operate in PAIRS!

What's the relationship between interior angle and exterior angle?

### Sum of Interior Angles of a Polygon

Reference: Study Notes (p12)

What general formula can you conclude from the above - to find sum of interior angles of a n-gon ?

### Exploration: Sum of Exterior Angles of a Polygon

Reference: Study Notes (p12): On the given handout...

Post lesson discussion - after the "cutting"/ "tearing" exercise:

Sum of Exterior angles of a Polygon = 360 degrees [sum of angles at a point]

### Polygons: A summary of Quadrilaterals

Attempt this quiz to check well well you know these quadrilaterals

diagonal is a line joining two nonconsecutive vertices of a polygon or polyhedron
(source: http://en.wikipedia.org/wiki/Diagonal)
Read more about diagonals at the source.

## Wednesday, 30 July 2014

### Revision Papers for Level Test 2 - MGS papers

Please note that the following have been uploaded to the GoogleSite - for your reference & practice:
GoogleSite > Mathematics > Class page > Folder: 02 Revision

Note that we will not be printing this revision paper for you.

## Tuesday, 29 July 2014

### Basic Geometry: An Introduction

Today, we started the topic by understanding the vocabulary of Geometry - some commonly used words related to the topic and what they mean.

Preparation for the next lesson:

Homework - after going through the above, attempt the 1st sheet of homework (Unit 13.1 Basic Geometry)
Do on this sheet of paper, at the spaces available.

For Q5,
• Form an equation with the unknowns and the given angles
• remember to write down the reasons
• Refer to the lesson in GoogleSite on how to present the working properly.

## Saturday, 26 July 2014

### [Some Tips] Presentation of Working for Word Problems

As iterated in class (many times), it is important for us to present our working clearly so that whoever reading your working (and answers) is able to understand your train of thoughts. In addition, proper working presentation is also a demonstration of your understanding of concepts.

Below is a guide (by Mr Desmond Peh) on how you should present your working, especially when answering to word problems.

• By the way, can you spot one part of the working that could be further improved?

## Thursday, 24 July 2014

### Speed: The Science of Lightning

Study Notes (p19): Challenge (Tier C)

Here are some additional information on the discussion:

Which media does sound travel fastest in?
• Vacuum? Air? Water? Solid?

## Tuesday, 22 July 2014

### Ratio: Study Notes Q16 Suggested Answer

Please see below, the suggested way of solving the problem (using algebra, right from the start).
This would be a good strategy, especially if you are required to SHOW the answer is 40/89

While by substituting numbers work (as most of you have attempted in that manner), you would notice that you could substitute different sets of numbers in the expression, and yet you still get 40/89; then how would you explain that?
(there's where algebra comes in to help generalise their explanation....)

## Monday, 21 July 2014

### Ratio - Pathologists and Ratios

Study Notes (p3)

Click HERE to view the data submitted.

What pattern did you observed amongst the ratios computed?

For those who are interested to find out more, HERE's a thesis paper on "The Foot Length to Stature Ratio: A Study of Racial Variance" (1990)

### Ratio: Homework

Homework - for tomorrow's discussion:
Study notes: p5 to p9
• Class Work 1 (Tier A)
• Class Work 2 (Tier B)
• Class Work 3 (Tier B)
• Class Work 4 (Tier C)

## Sunday, 20 July 2014

### Summative Assessment: Percentages

Re: Reschedule of assessment for those who are unable to turn up on 18 July (1.30 pm)

Hi Everybody

As you did not turn up for the summative assessment on Friday 1.30 pm (for various reasons),  I've re-scheduled you to take the assessment on
Day/ Date: MONDAY 21 July
Time: 3 pm
Venue: S1-01 classroom

Remember to bring along your calculator.
The maximum duration of the paper is about 30 minutes.
You may leave immediately when you finish the paper.

With regards
Ms Loh

Who needed to attend:
 2 KAY SANDY MAUNG
 3 OON CHWEN YUEH, CELEST 4 WOON YOKE XUAN 5 CHRISTOPHER YONG WEI JIE
 12 JUSTIN LIM
 21 TEE HAO WEI, OWEN

## Saturday, 19 July 2014

### Inverse Proportion: Discussion of Answers to Examples 2 & 3

Below is what we discussed, and how we should present our working:

## Thursday, 17 July 2014

### Level Test 2 Info

Information was posted in the GoogleSite Announcement Page

## Wednesday, 16 July 2014

### Direct Proportion: Quick Check

You may click HERE to access the Form or attempt the questions in the embedded form below

As discussed in class, here's how the working to the questions to be presented:

## Monday, 14 July 2014

### Class Work 3(Tier C)

3. The median of a set of numbers is 4.5. Given that seven of the numbers are 9, 2, 3, 4, 12, 13 and 1, find the eighth number.

Let a be the unknown eighth number.

Numbers in ascending order
1, 2, 3, 4, 9, 12, 13

4 is the median of the seven numbers.

4.5 = 4 + a
2
4.5 x 2 = 4 + a
9 = 4 + a
a = 5
The eighth number is 5.

4. A box contained five cards numbered 1, 2, 3, 4 and 5. A card was drawn from the box, its number noted and then replaced. The process was repeated 100 times and the table below shows the resulting frequency distribution.

Numbers              1        2        3        4        5
Frequency           21       x        y       18      17

(a) Show that x + y = 44
(b) If the mean of the distribution is 2.9, show that 2x + 3y = 112
(c) Find the value of x and y
(d) State the mode and the median of the distribution.

a)
The total frequency is 100 as the process was repeated 100 times.

100 = 21 + 18 + 17 + x + y
100 = 56 + x + y
44 = x + y

b)
2.9 x 100 = 290
21 x 1 + x x 2 + y x 3 + 18 x 4 + 17 x 5 = 178 + 2x + 3y
=  290
290 = 178 + 2x + 3y
112 = 2x + 3y

c)
Since 44 = x + y and 112 = 2x + 3y,
y = 112 - 44 x 2
= 112 - 88
= 24
x = 44 - 24
= 20

x = 20 and y = 24

d)
Numbers              1        2        3        4        5
Frequency           21      20      24      18      17

From this diagram we can tell that the mode is 3.

The median number will be the mean of the 50th and the 51st number.

Numbers which are 1 are the numbers from 1 to 21.
Numbers which are 2 are the numbers from 22 to 42.
Numbers which are 3 are the numbers from 43 to 66.
As 50 and 51 are in the range of numbers which are 3,
the median is 3.

### Linear Graphs: Worked Solution to Summative Assessment

Click HERE to view the Playlist that explains the solutions to the question by parts:

## Sunday, 13 July 2014

### Data Handling HW6B: Question 2

Here the two versions of Frequency Table & Histogram presented by some of you.

Version 1

Version 2

You may click HERE to view the spreadsheet on how to calculate the frequency within the range.

## Thursday, 10 July 2014

### Spreadsheet functions for Mean, Median, Mode

[Study Notes Class Work Tier A Q2 & Q3 (p18)]

• You will not be able to edit this file.
• Go to FILE > MAKE A COPY to save a copy of the spreadsheet into your GoogleDrive.
• Rename it as "Data Handling (Study Notes) P18Q2Q3".
• You are going to apply a few functions that would aid you to compute the mean, median and mode.

## Wednesday, 9 July 2014

### Frequency Table & Histogram

[Study Notes: p10]
Here's another way that a Frequency Table may look like:

This is how the histogram looks like

Homework
• Attempt Homework 6B
• Preparation for next lesson's discussion: Mean, Median, Mode
• p16-p17: Read through what Mean, Median, Mode are
• p17-p19: Attempt Tier A (Q1 to Q3) and Tier B (Q1 & Q2) questions

### Data Handling: Frequency Table and Histogram

During the lesson, we did the following:
• Data Gathering - when we collected data from each and everyone who's present in the class. Today, we have 21 data points [absent: Elgin and Celest]

• Tabulation of Data - we organised the raw data in a frequency table as shown on the board.
• Note 1: To account for every data point, we 'cancel' off the data point once we noted them in the table.
• Note 2: We add up the numbers in the "Frequency" row to check if it tallies with the total number of data points.

• Next, we will be representing data in a statistical representation. In this case, we are using a Histogram

## Tuesday, 8 July 2014

### Data Handling 6.1 Activity 2 (p4)

The following diagrams are obtained from the interactive tool (in AceLearning portal):

Among the 4 graphs (Line Graph, Bar Graphs, Pictograms, Pie Charts), one of the graphs is NOT appropriate to represent the information.
·       Can you identify the one that is not appropriate?
·       Why do you think it's not appropriate?

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

Enter your response in the blog comments, remember to include your group at the end of your posting.

## Monday, 7 July 2014

### IMPORTANT DATES: Assessment Matters

Dear S1-02

As spoken, we'll be having the Summative Assessments after school these 2 weeks.

The schedule is as shown:

Please report to the Seminar Room (Block C, Level 3, opposite SST Inc) at 1.20 pm to get ready.

Muslim boys from S1-04 will report at 2.15 pm to the Info Hub.

Alternative Assessment/ Performance Task

21 - 25 July

Level Test 2

End-of-Year Examination

## Sunday, 6 July 2014

### Self-Directed Learning: PERCENTAGES - Homework Submission

The following have yet submitted the self-directed learning Homework.
Please submit by Term 3 Week 2.

 3 OON CHWEN YUEH, CELEST 4 WOON YOKE XUAN 6 FYODOR LEE JUN DE 7 HONG DOMINIC 10 JOSHUA CHUA TZE ERN 11 JOSHUA YEW JEK YONG 13 KHOO BO SI 14 LEW JIAJUN Jerry 20 RICHMAN KUM CHO HOWE 22 WONG KANG

### Linear Graphs - Determine Equation

Here's a summary of Linear Graphs

Here's how you could solve the 4 problems in p29 (Study Notes): [Playlist - 4 clips]

## Saturday, 5 July 2014

### T1W1 Homework

Dear S1-02

(A) Linear Graphs

In class, we had completed the discussion of 3 out of 4 questions in p29.
Complete Q3 on your own and watch the clip that's posted in an earlier post (click HERE) that explains how to approach and solve such problems.

In addition, go through the questions in p30 and answer the questions in the following blog posts:

(B) Data Handling

At the end of the lesson, you were given the set of Study Notes for "Data Handling".
Please do the necessary preparation (click HERE to read the instructions were in the earlier post below)

Complete the above tasks before we meet on next Tuesday.

## Friday, 4 July 2014

### (Flipped Learning) Introduction to Data Handling

Please refer to your study notes (p3 to p5).

The materials (including relevant video clips) for the activities in this lesson are posted in the GoogleSite > Mathematics [click to access the page directly].

We will be discussing Activities 1, 2 & 3 in the next lesson.

### Homework: Study Notes (p30) Discussion 1

How would you determine if the points A (2, -5) and B (5, 2) lie on the straight line y = 3x - 5?

Remember to enter your group number.

### Homework: Study Notes (p30) Discussion 2

Describe the various ways that we can use to find out if 3 given points lie on the same straight line.

Remember to enter your group number.

## Thursday, 3 July 2014

### Extended lesson on 8 July 2014

Dear S1-02

As spoken on Monday, we will have an extended lesson next Tuesday (8 July 2014), from 2 pm to 3 pm.
Venue: S1-02 classroom.

All students are required to attend the lesson as new content/materials will be delivered during the lesson.

### (Flipped Learning) Sketching of Graph

1. Watch the following video clips (there are 4 altogether).

2. Make reference to the Study Notes, p28 to complete the exercise.
You have to complete the 4 questions in p28 in preparation for the Discussion & Quiz in the next lesson.

In the following question,

Would you accept the following answer?
(Ans #1) y = x + 4
(Ans #2) y = 3x + 1

### Discusion: HW8E Question 4

In the following question, one important consideration is the "mirror" line.
Where do you think the mirror lines going to be? How many mirror lines are there altogether.

Strategy: Sketch the graph on the paper and figure out.

This is one possibility: when the mirror line is the y-axis.
Can you tell the equation of the "reflection"?

This is one possibility: when the mirror line is the x-axis.
Can you tell the equation of the "reflection"?

## Tuesday, 1 July 2014

### How steep can the steps be?

We spoke about gradient of slopes in the class... now, look at the photo - are you able to tell (roughly) how steep the staircase is?

Photo: Bergen in Norway