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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,879

Hi MIF;

Really gives the feeling that you are zooming in! If you threw a couple of colors in there and some sounds it would really be a psychedelic event.

Anyway, it looks and works fine for me.

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,786

hi MIF,

That looks excellent; I haven't found any bugs. I've emailed the link to my colleagues at school to have a look and to get some pupils trying it out. I'll let you know if I get any helpful feedback.

Thank you very much!!

Bob

*Last edited by bob bundy (2011-11-15 21:29:45)*

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,559

Look forward to the feedback, bob

bobby: your suggestion of color sounds possible. Sound effects may be good too!

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,879

Hi MIF;

What sounds will you choose?

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,559

In: Vrooom.

Out: Whoosh.

Left/Right: Chugga chugga.

Any better ideas?

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,879

Hi;

In order to evaluate those I would have to hear them.

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,559

Added the sounds ... use refresh to make sure you have latest version.

If you can find better sounds let me know.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,879

Hi MIF;

Sounds pretty good.

**In mathematics, you don't understand things. You just get used to them.**

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,559

You can be justifiably proud. Hope the frogs settle in happily, have they declared the water "knee-deep"?

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,786

Hi MIF

Did you mean?:

Zac Brown Band Knee Deep

"Gonna put the the world away for a minute

Pretend I don't live in it

Sunshine gonna wash my blues away

...................

Wishing I was knee deep in the water somewhere

Got the blue sky breeze ..................

.........................

Never been so happy

Never felt so high

And I think I might have found me my own kind of paradise"

But my frogs preferred wallowing in the mud at the bottom of the old pond.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,559

That reply was more deep than mine! I was making a frog noise "knee-deep" ... or perhaps your frogs are from the "McGurk" clan?

Fascinating that your frogs have such a homing instinct.

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,559

I have started putting some words on the Zoomable Number Line page.

I was wondering if any of you (particularly Mr Bundy!) would like to add some ideas on how best to use this?

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,786

hi MIF,

I'm working on it.

(i) I'll suggest some other pages that could link to it.

(ii) I'll think up some suitable words to go with the interactive bit.

Back later.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,786

hi MIF

(i) My suggestions for which pages could have a link to the zoomable number line and where on the page.

http://www.mathsisfun.com/decimals-menu.html

What a Decimal Number is ...

http://www.mathsisfun.com/decimals.html

Large and Small

http://www.mathsisfun.com/index-notation-powers.html

heres more

http://www.mathsisfun.com/rounding-numbers.html

heres more

Bob

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,786

hi again,

And some suggestions for (ii) what could go on the page.

(More may follow when my creativity level has recovered. Spent too long on an unprovable identity!)

Copied then added to what is there. Whoops. I've lost all the formatting.

What is this all about?

See that numbers behave the same, whether they are 1,2,3, or 10,20,30, or 0.01,0.02,0.03, etc...

It is a great way to learn about decimals:

Zoom in and look at: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, ...

Then ask: what is 0.9 + 0.1 ?

Do the same after zooming in further:

What is 0.09 + 0.01?

What is 0.19 + 0.01?

What is 0.99 + 0.01?

MY SUGGESTIONS

You can track left and right along the line by clicking on one of the arrows.

You will track faster if you move outwards along the arrow.

Try this. At the start you will see the counting numbers wizz past.

Stop when you reach 100.

Go back to zero.

Zoom in to show 0.1, 0.2, 0.3, .........

Now try tracking right. The tenths wizz by.

How long does it take to reach 100 now?

Try zooming in to 0.01, 0.02, 0.03, ......

How long does it take to track across to 100 now?

Test yourself

Start at 0. Use the zoom and tracking to find these numbers

3.4

17.85

-17.85

100.00357

COMMENT. If a learner can do these he / she has a pretty good understanding of the way the decimals behave, I think.

Bob

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,559

Nice Bob, maybe your words could go instead of mine.

bob bundy wrote:

(More may follow when my creativity level has recovered. Spent too long on an unprovable identity!)

I can easily wait ... take your time.

And don't worry about formatting, I can do that.

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,786

Good morning MIF,

Your words are good. I wrote mine to go after, not instead.

Bob

*Last edited by bob bundy (2011-12-12 19:24:42)*

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**gyanshrestha****Member**- Registered: 2007-11-06
- Posts: 41

what are the uses of zoomable number line?

http://gyan.talkacademy.com.np

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,786

hi gyanshrestha

If you are a competent arithmetician, then I can understand why you might wonder. I have taught children for 38 years and have frequently found some who do not have a good grasp of how the decimal number system works.

This interactive resource shows that it is possible to subdivide each interval into 10 parts so learners can begin to understand tenths hundredths etc ... 0.1, 0.01, 0.001 and so on. They can see how decimal place values work and get a feel for 'infinite' sub-divisibility.

The text in the posts above show some of the applications:

eg. what comes next after 0.7, 0.8, 0.9 ....? And of course you can ask this question at any level.

eg. Finding a number on the line. I used the example of 100.00357. First the learner has to track to 100. They might do this the slow way by counting up in ones, but how much better to realise that you can zoom out a level and go up in tens. Then you have to zoom in and in and in so that you are at 100.00 Understanding that needs to be done is a crucial learning step. And, being interactive, the learner can immediately see if they have gone off track. Then they must zoom in and track to find the next digits. You just cannot do that on a whiteboard or on paper!

I am working in a primary school ( aged 4 to 11) for the next few days so I am going to encourage the teachers to give it a try. I think they will find new uses that I haven't thought of yet.

Here's a more advanced challenge for you. If each 'track one scale unit' costs a single key press and similarly, each 'zoom up or down a level'; then what is the least number of key presses to go from the start position to 100.00357 ?

(Note: I don't know the answer yet. One of the great things about superior teaching resources is that you can set questions to which you don't know the answer but are nevertheless confident there is one.)

Bob

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,889

hi MIF

i think that there should be zoom in and zoom out buttons.a feature that would be very helpful is being able to draw intervals to find their intersection,but i'm not sure how doable that is...

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,559

Nice discussion ... as a result I have updated the program to respond to Up/Down/Left/Right keys. Have a try.

(Use refresh, look for version 0.83)

Bob, some of those ideas could be put on the webpage, too! "Race to 100.00357" sounds like fun.

anonimnystefy wrote:

being able to draw intervals to find their intersection

This is quite a good idea, but maybe deserves its own application.

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,786

hi MIF,

I'm in a school at the moment. I spoke to one of the teachers about the ZNL and straight away she could see the uses.

I've left a big notice in the staff room saying

**VISIT MathsIsFun.com**

When will the line be 'on the menu' ?

Yes! Add the race.

Bob

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,889

hi MIF

yes that is very practical especially for students that have a focus on algebra.

another thing.sometimes when i zoom in i go to far to the left and when i press the zero button it centers it but it also resets the zoom. it would be nice to have separate buttons for centering the number line at 0 and for resetting the zoom.

one more idea.you could add a place to type in a number and it finds it instantly(well,maybe not instantly) on the line,so that e.g. i don't have to have my arm fall off just to reach 154.7

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,786

hi Stefy,

If 0 goes 'off-centre', just move your pointer a little and the centre will move as you want.

one more idea.you could add a place to type in a number and it finds it instantly(well,maybe not instantly) on the line,so that e.g. i don't have to have my arm fall off just to reach 154.7

Please don't ask for this. You are a good mathematician so you have only a small need to find 154.7

The line is a teaching aid and I want someone's arm to fall of finding a particular value. That way they learn!!

Hope you don't mind too much. I'm sure we can club together to buy you a new arm!

Bob

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,889

hi bob

i don't mind the arm that much anyway!

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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