Showing posts with label Android app. Show all posts
Showing posts with label Android app. Show all posts

Monday, February 20, 2017

Math Garden

Spring Math: Math Garden

In this app, the Natural Numbers are represented as Vegetables (plants): 

Fundamental Theorem of Arithmetic:
(From Wikipedia)
In number theory, the fundamental theorem of arithmetic, also called the unique factorization theorem or the unique-prime-factorization theorem, states that every integer greater than 1 either is prime itself or is the product of prime numbers, and that this product is unique, up to the order of the factors.

Therefore, if each decomposition of a number into its prime factors is unique, each number will have a unique form when it is shown as a plant.
But it is not exactly like that. Depends on the order in which the factors are multiplied.

This is shown in the following app videos:

There are two versions of Math Garden (Android) 

Kids Math Garden:
Video: 
 

Math Garden:
Video:

Details:
The general operation is similar to that of plants:
Seeds fall from the sky
They should be planted. And then grow the plant corresponding to the seed (and the number chosen).
When the time comes to harvest dandelions, the plant is plucked from the ground.
Then the seeds that it has generated are released.
And the seeds return to heaven.

The particular operation is similar to that of the numbers:
If two unseeded seeds overlap, they add up.
If two seeds are planted, the plants multiply.

The plants are structured in branches, forking in function of the prime numbers that compose the factorization of the number.

Plants multiplied underground, often have a structure different from plants planted in a single blow.
(Multiplied plants do not have the usual order of a well-made factorization)
Each plant generates as many little dandelions as the number that indicates its seed, Having any of the structures that may have.

The program has 30 furrows one behind the other to be able to plant.

I hope it will be useful to teach maths. 

Math Garden:
Pythagorean Garden:
3²+4²=5²
5²+12²=13²
8²+15²=17²
7²+24²=25²
Pythagorean Garden


105 Plant In the Math Garden
Variants: The 6 subspecies:
105=3*5*7
105=3*7*5
105=5*3*7
105=5*7*3
105=7*3*5
105=7*5*3
(In invented mathematical plants, of course!!!)
Order of multiplication  vs. Factorization



UPDATE:  (August 2017)
Fractions: 

 


Origin of Math Garden:
Jessica's Drawing of 96
(From Simon Gregg' work)



And Nummolt's:
"Touch Natural Numbers"  
And
"Touch Integers Z"

Wednesday, October 5, 2016

Place Value Time

After the experience of my old "Time Calculator" (for mathcats.com 2004) I tried to develop an app that explains how this webpage subtract time.

Over the years I have received all kinds of comments on how to make this calculation.
This time, I tried to explain graphically how the original application does.


And I think I've managed to build what should have been the original application.
What was missing was to be able to modify the difference between the two dates.

(and save last configuration) 

I must thank all those who have been making comments over many years

Here you can find the new: "Place Value Time"  (for Android devices) 
( https://play.google.com/store/apps/details?id=com.nummolt.time.place.value  ) 

 Here is the video of the 'Place Value Time' Android app:


 In the video:
  • - From countdown to elapsed time.
  • - my age.
  • - when I should have celebrated my 500,000 hours of life.



The app is available on Google Play, Samsung Galaxy Apps and Amazon.
Place Value Time - Google Play
Place Value Time - Amazon
Is a paid app.(the paid version of the previous 'Time Calculator' (Android)



Sunday, May 8, 2016

Noting mathematics education in the world, from the statistics page of my Android apps

This is just a small observation, based on my own stats:
As the numbers that I show are not too high, observation may not have enough value.

Typically, the math apps downloads have a proportion of users fairly well distributed among all countries. However, there is always a predominance of the US downloads:

Example graph of a usual app of active users statistics:


(humble numbers related to a calculator)

In my  Google Play page, there is one of the oldest applications that I've done, devoted to linear algebra and the  Gauss-Jordan elimination as a method of solving two equations with two unknowns.

For the application to be a little more attractive, I called it "Adding apples and oranges", referring to an equation are getting really different variables to give a result.


The proportion of current statistics of this application are quite different from other applications. There is a predominance of US downloads:

(humble numbers related to a Apples and oranges app)


While this difference so marked, it makes me think:
It could be that the education authorities of the US had greater knowledge of applied mathematics than education authorities of other countries?

Knowledge of the intellectual basis of the information revolution which we live has influenced the educational guidance of the US?
Or is the result of many parents with deep and old computer knowledge?

What is it that justifies this big difference?

I've searched Common Core related items with the elimination of Gauss-Jordan:
Here are some examples about the related items:

CCSS.MATH.CONTENT.8.EE.C.8 - A, B, C.
CCSS.MATH.CONTENT.HSA.REI.C.6
CCSS.MATH.CONTENT.HSA.REI.D.12


I can not draw a conclusion. Just leave the data in case anyone is able to solve these questions.




Thursday, December 31, 2015

Touch Fraction ℚ (1.4.x)


New version of Android App "Touch Fraction ℚ"  (version 1.4.x and up)
https://play.google.com/store/apps/details?id=nummolt.touch.fraction


Evolution of the app over the years: (1993-2015)
In 1993 I developed the first executable (for Windows 3.1) of Touch Fraction ℚ (Racional.exe):


It was my first attempt of to show an interactive representation of Rational numbers as fibres in (Z * Z {0}) and arrangement in Q.
As the Rational representation in Wikipedia:  Rational Numbers:


In 2013 I made the new version of the app: The translation of the original executable to the Android OS.
The interaction became extended to the fraction:
The pie fraction to navigate across the fractions, and the rational representation to navigate across the equivalent fractions. (and select the range of available denominators)



In 2015 after the development of Touch Integers ℤ (+ - × ÷) (https://play.google.com/store/apps/details?id=com.nummolt.touch.integers)
This time, I was able to afford the next step:
Explain fractions and rational numbers as the prime factorization of its members: numerator and denominator.
This is the new version of Touch Fraction ℚ:




Interact with the fraction, build fractions adding or removing prime factors in the numerator or in the denominator.
Simplify fractions dragging common prime fractions to the "common" zone, and invert fractions with the "^-1" button.  

Touch Fraction ℚ is a complete tool to understand positive fractions, negative fractions, positive and negative numerators, positive and negative denominators, equivalent fractions, and inverted fraction.