The Language of Mathematics (8): Multiplying and Dividing

Table of contents listing all instructional math videos available from Chycho TV at http://www.chycho.com/?q=math_Table_Contents

List of videos that are available for download at http://www.chycho.com/?q=math_download_chycho

INTRODUCTION:
http://www.chycho.com/?q=Introduction_Instructions

During the last few years the education systems in Canada and the United States has been eroding. Students have been crammed into larger class sizes while the quality of teaching has deteriorated, in large part due to a lack of funding from local and federal governments.

John Ralston Saul, one of Canada's most celebrated authors and essayist, has warned us that "Canada's democracy... is eroding with every dime deducted from education budgets."

I have stated previously that I believe "as a collective we must understand that democracy can only exist in a society with an educated populace, and the right for self-governance can only be obtained through knowledge." I also believe that as long as the Internet remains Neutral, we, as a global community, can make a difference. We can fill the gap left behind by our governments and be proactive in educating our children

Sharing our communal experiences and knowledge is the essence of the Internet and chycho.com is proud to be a part of this movement. The information contained and conveyed through this medium is what will shape our future, and this site was created to represent a unique personal perspective and to contribute in bringing about positive changes.

As a result I have decide to produce instructional math videos to help those that want to improve their abilities in communicating in the language of mathematics. The videos are available on Chycho TV Located in the top right corner of http://www.chycho.com. Even though these videos are geared towards high school students, they will also help those in elementary school and those that are struggling with certain college and university courses.




The format of the videos is as follows: Lessons are in large part self contained and most have exercises which should be completed before proceeding to the next lesson. To help people understand a specific topic I have included answers to the exercises and a video showing how I solved the problems. Hence all exercises will have a video showing the exact steps taken to get the correct answer. Please make sure that you view these videos if you are having difficulty solving the problems.

During the next few weeks and months, possibly years, I hope to be able to provide a vast library of resources for those that wish to finally understand the language of mathematics.

If there are certain areas that you are having problems with or wish me to discuss further then please send me a message or post a comment at my website. Even though I can not guarantee that I will be able to properly represent a topic I will try my best to produce a lesson if there is strong enough demand for a specific topic.

I hope these videos will help people learn how to communicate in the language that we have chosen to understand the world around us in a scientific manner, in the language of mathematics.

Best

Chycho
http://www.chycho.com/

Category:

Education

Tags:

• Algebra
• geometry
• Math
• Mathematics
• Number
• school
• lessons
• problems
• homeschool
• numbers
• education
• teaching
• learning
• home

[2JROLLn]

I just want to say thank you for your videos you have made math less fear full.

[chychochycho]

my pleasure, I'm glad to help :) 

[bodhidarma1]

Ughh. You lost me as a fan on this one. People need to stop learning to do basic operations by working right to left on paper, or at least less emphasis should be placed on it. Seriously, try using this method in your head to add two three digit numbers together and you'll quickly realize its limited worth.

Math teachers, stop doing this!

Teach it the right way. Left to right, done in steps. It makes head math a hundred times easier.

[chychochycho]

you should start making videos and teaching it the other way.

[bodhidarma1]

Btw, what you did with that wall chalk in the first few videos... and the measurements, and knowing where to point the chalk... it was an awesome demonstration of the power of mathematics. I'm still left wondering how you did it exactly.

[chychochycho]

hehe, i was looking at a very small screen :)

but i like the math explanation more :))

[DeWittAlbright]

Really good work and you make it really interesting.

I love the concept.

[Thaperfect1]

I've just been accepted at uni and i can't even do division :( As part of my condtional offer i must pass my maths exam to be able to do the degree next year. Im tryin to enjoy maths but im finding it really hard. Im struggling so much with this part :( Just need to keep trying harder. :(

[CHRISTMASBASTARD]

I love your open approach... we need to stop following stereotypes cuz its killing us. My technique to adding and subtracting any number over 10 which I learnt from using a soroban is: x±y=z, 10-y=a, x±10±a=z, if y is -y then 10 is -10 and a is +a and if y is +y then you have the opposite. i.e. 7+8, 10-8=2 , 7+8=7+10-2=15. i.e 17-9, 10-9=1, 17-9=17-10+1=8.

[talkotime]

one thing I always found frustrating as kid is that they always referred to carrying the ten as carrying the one. I never understood how a ten could just magically turn into a one.

[mmille10]

Corrections: In the multiply by tens part I should have said: "but if a result is more than 99, you carry". To explain "the zero placeholder" one could say, "since we're not going to be getting any ones out of this multiplication, we'll go ahead and put a zero here."

[mmille10]

In the 25 x 12 example, it would really be better if you made place value explicit in the method. You multiply and then you add to make the first line result: 2 x 5 = 10 (just leave a zero placeholder in the ones place), 2 x *20* + *10* (from the carry) = 50. Now you start multiplying by tens, but if a result is more than 100, you carry. So you put a 0 in the ones place as a placeholder in the second line result:, and then *10* x 5 = 50, 10 x *20* = 200. 200 + 50 = 250. Now add the two lines.

[k1ngross]

Very good, this one went a little fast I feel though. Maybe a little more explanation on why you start adding and subtracting stuff would have been helpful.

Thankfully this is a video and I could watch it a couple times to get it in my head :D

Thanks