37 x 99

= 37 x (100 - 1)

= 37x100 - 37x1

= 3700 - 37

= 3663

Devise ONE arithmetic problem that you could illustrate how distributive law could be applied to simplify the solving process.

Enter your "arithmetic problem & solution" in comments.

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Chap 5 Algebra: An Application of Distributive Law

## Self-Directed Learning (I)

## when we meet... in Term 3

## Term 3 Week 3 Maths Test

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*Source: Teacher.TV (**http://www.teachers.tv/**)*

**Safety In Numbers** Mathematician Marcus du Sautoy reveals how the language of maths is used to construct the complex codes that we encounter in everyday life. Learn about the amazing use of PRIME NUMBERS in our everyday life.

(http://www.teachers.tv/video/3501)

**Zero to Infinity **In this programme, mathematician Marcus du Sautoy explains how humans have developed numbers for their mathematical needs. Hear about the Invention of **Zero** and have a better understanding of **Infinity**. Can we divide a number by Zero? Is *Infinity* the biggest number? (http://www.teachers.tv/video/3500)

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Found!!! The biggest**Prime Number** yet...

Click HERE to read article.

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Year 2010

Refer to Brainworks (in textbook p103) - It shows an example how distributive law could be used to 'simplify' complex arithmetic:

37 x 99

= 37 x (100 - 1)

= 37x100 - 37x1

= 3700 - 37

= 3663

Devise ONE arithmetic problem that you could illustrate how distributive law could be applied to simplify the solving process.

Enter your "arithmetic problem & solution" in comments.

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ODD week

Tuesday 0800-0900

Thursday 0900-1000

Friday 0900-1000

EVEN week

Tuesday 1430-1530

Thursday 0800-0900

Friday 1030-1130

Tuesday 0800-0900

Thursday 0900-1000

Friday 0900-1000

EVEN week

Tuesday 1430-1530

Thursday 0800-0900

Friday 1030-1130

The following topics will be covered in the Maths Test

Chapter 4: Introduction to Algebra

Chapter 5: Algebraic Manipulation

Chapter 9: Ratio, Rate and Speed

Chapter 16: Data Handling (including Mean, Median, Mode)

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This term, we have earmarked 2 sub-topics for you to learn on your own... own time own target (to be completed by Term 1 Week 9).

**Chapter 9.2: Average Speed **

You are expected to complete sub-topic by 15 May 2010. A Pop-Quiz has been scheduled on 18 May 2010 (Tuesday).

**Chapter 9.3: Speed**

Apart from textbook and workbook, recommended resources and learning activities will be delivered through the AceLearning Portal and the Maths Blog.

**As these 2 sub-topics are not going to be covered in the class, please check/clarify with Ms Loh (Face-to-face or virtually) when you are in-doubt.**

You are expected to complete sub-topic by 15 May 2010. A Pop-Quiz has been scheduled on 18 May 2010 (Tuesday).

Apart from textbook and workbook, recommended resources and learning activities will be delivered through the AceLearning Portal and the Maths Blog.

(http://www.teachers.tv/video/3501)

Article:

Found!!! The biggest

Click HERE to read article.

(http://www.teachers.tv/video/43462)

Source: Teacher.TV (http://www.teachers.tv/)

Source: Teacher.TV (http://www.teachers.tv/)

**Seaside Triangles** - How properties of triangles become useful in real world applications.

(http://www.teachers.tv/video/37910)

**Surface Area of an Octagon** - Step-by-step process of working out the area of an octagon

(http://www.teachers.tv/video/43382)

(http://www.teachers.tv/video/37910)

(http://www.teachers.tv/video/43382)

This video clip, Statistics: Decisions Through Data shows how data (in the study of Statistics) has enabled mankind to make big and small decisions, that either impact the individuals or the bigger community.

Look out for the following segments:

- Describing Data

- Producing Data

- Conclusions from Data

~~~~~~~~~~~~~~~~~~~~~~~~~~

Watch this video clip The Business of Farming

*Source: The Futures Channel (**http://www.thefutureschannel.com/index.php**)*. Note: It may take a while to stream the video clip

*This video about...* There are more than 350 different commodities grown in California. In a state that provides approximately 15 percent of U.S. agricultural products, statistics are an important tool for agricultural economists to keep up with supply and demand. Let's hear how the statistics help farmers to make decisions!

Look out for the following segments:

- Describing Data

- Producing Data

- Conclusions from Data

~~~~~~~~~~~~~~~~~~~~~~~~~~

Watch this video clip The Business of Farming

36 x 101

ReplyDelete= 36 x (100 + 1)

= (36 x 100) + (36 x 1)

= 3600 + 36

= 3636

78 x 103 = 78 x (100+3)

ReplyDelete= 7800 + 234

= 834

38 x 199

ReplyDelete= 38 x (200 - 1)

= (38 x 200) - (38 x 1)

= 7600 - 38

= 7562

50 x 22

ReplyDelete= 50 x (20+2)

= 50 x 20 + 50 x 2

= 1000 + 100

= 1100

36 x 101

ReplyDelete= 36 x (100 + 1)

= (36 x 100) + (36 x 1)

= 3600 + 36

= 3636

60 x 48

ReplyDelete= 60 x ( 50 -2 )

= 60 x 50 - 60 x 2

= 3000 - 120

= 2880

72 x 102

ReplyDelete=72 x ( 100+2)

= 7200+ 144

= 7344

104x99

ReplyDelete=104x(100-1)

=10400-104

=10296

78x103

ReplyDelete= 78x (100+3)

= 1800 + (78x3)

= 1800+234

= 2034

97 x 101

ReplyDelete= 97 x (100 + 1)

= 97 x 100 + 97 x 1

= 9700 + 97

= 9797

22 x 98

ReplyDelete= 22 x (100 - 2)

= 22 x 100 - 22 x 2

= 2200 - 44

= 2156

9999 x 9999

ReplyDelete= 9999 x (10000 - 1)

= 9999 x 10000 - 9999 x 1

= 99990000 - 9999

= 99980001

To all who have submitted so far... Well done :)

ReplyDeleteThe rest... waiting for your examples...

31x41

ReplyDelete=31x(40+1)

=31x40+31x1

=1240+31

=1271

678 x 99

ReplyDelete= 678 x (100 - 1)

=678 x 100 - 678 x 1

=67800 - 678

=67100

374 x 61

ReplyDelete=374 x 50 + 374 x 10 + 374

=18700 + 3740 + 374

= 22 814

170 x 710

ReplyDelete=170 x (700+10)

=119000 + (10 x 170)

=119000 + 1700

=120700

100x239

ReplyDelete=100x(240-1)

=100x240-100x1

=24000-100

=23900

This comment has been removed by the author.

ReplyDeleteThis comment has been removed by the author.

ReplyDelete98 x 102

ReplyDelete= 98 x (100+2)

= 98 x 100 + 98 x 2

= 9800+ 196

=9996

This comment has been removed by the author.

ReplyDeleteThe 6th additional posts are fine too :)

ReplyDeleteOne for discussion: Grace's example -

170 x 710

= 170 x (700+10)

= 119000 + (10 x 170)

Would be good to further 'breakdown' in the process so that we deal with 'smaller' numbers first. Can consider:

170 x 710

= 170 x (700+10)

= 170x700 + 170x10

= 170x7x100 + 1700

= 1190x100 + 1700

= ....

On the other hand, it's not so common to use distributive law on numbers that are not near the 'hundreds'