Touch decimals: Part 1: References

New Touch decimals: free Android app: Part I

Touch decimals,Place value ±

Introduction:

This is the application with a longer history among which I developed in www.nummolt.com.

The first version, made after two failed attempts was published in 1997:

I named it nummòlt, and in fact was the fundational application of nummolt.com.

Nummòlt was a application developped in C ++, and it was my first OOP program:

(Old nummòlt download page)

It was one of many attempts in the nineties to represent numbers graphically to kids.

I will like to remember some of the contemporaries who tried to represent numbers graphically:

Jacobo Bulaevsky: and www.arcytech.org page:

(Rebuilt by Jill Britton and Suzanne Alejandre of MathForum)

http://britton.disted.camosun.bc.ca/baseten/instructions.html

http://mathforum.org/varnelle/howto.html

http://britton.disted.camosun.bc.ca/patterns/patterns_d.html

(Jacobo Bulaevsky died in 8/13/2004)

(Base Ten Instructions)

Brian Sutherland and his: our-montessori.com:

http://web.archive.org/web/20060113011625/www.our-montessori.com/home.html

A rebuild of the Original:

http://www.our-montessori.ca/

http://ethereal.utm.utoronto.ca/our-montessori/math/stampgame.php(needs Shockwave player ')

http://ethereal.utm.utoronto.ca/our-montessori/math/largebeadframe.php(needs Shockwave player ')

(Stamp game)

In collaboration with Wendy Petti of MathCats, in 2003 we did the "Place Value Party"

http://www.mathcats.com/explore/age/placevalueparty.html

With the "place value" shaped as floors of a virtual birthday cake:

(MathCats.com Place Value Party)

In recent years, with the advent of affordable graphic tablets, there are new approaches:

Mainly: Ulrich  Kortenkamp (The creator of Cinderella). The Place Value Chart

https://itunes.apple.com/us/app/place-value-chart/id568750442

(Kortenkamp: Place Value Chart: iTunes)

(Here I must recommend the book: "Early Mathematics Learning: Selected papers of the POEM 2002 Conference": https://books.google.es/books?id=Lui3BAAAQBAJ ) 

And also:
Christian Urff: Rechentablett:

https://itunes.apple.com/de/app/rechentablett/id574825573

(Urff: Rechentablett: iTunes)

After the appearance of all this, I saw the possibility of bringing my previous programs under the way to represent numbers used by Urff and Kortenkamp.

This is my free: "Touch decimals, Place value ±" for Android.

Place value structure seen before, adding tokens with sign, and with the ability to create the neutral element of the sum: pairs of tokens positive - negative that do not alter the final outcome of any addition or subtraction operation.

https://play.google.com/store/apps/details?id=com.nummolt.math.value.place

(Nummolt's Touch decimals,Place value ±)

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