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- Maurici Carbó (nummòlt)

**Review Maurici Carbó (nummòlt)**

Not verified app developer

Architect and developer:

http://www.nummolt.com webmaster

http://www.mathcats.com collaborator.

Developer \'nummolt\' at: Google Play

Funded by: \'Double Struck Capital\'

Apps, approved by Google Play For Education, Android TV, Samsung apps and Amazon.

Educational apps development. (Mathematics)

Architect since 1993 http://arquitectes.coac.net/mcj/

Nummolt Youtube channel: http://www.youtube.com/user/nummolt

Nummolt Blog: "Mathematical engine mill": http://nummolt.blogspot.com

Web DevelopmentCross Platform App DevelopmentAndroid App DevelopmentEducation App DevelopmentMobile Game App Development

Web Development

I develop web pages and apps. Using: HTML5 + CSS + JavaScript + PHP. Connected to MySQL databases. Like: http://statcats.nummolt.com/

Cross Platform App Development

Multiplatform apps based in a right Html/JavaScript build, using WebView in Android. Example: "Ninedigits workshop" https://play.google.com/store/apps/details?id=mathcats.nummolt.ninedigits

Android App Development

I develop native Android apps. Educational math apps Also I develop traditional apps, using GPS and Google Maps API and other tools. Interested in the development of educational math resources. Experience collaborating with NCTM

This development company does not have reviews. If you have worked with **Maurici Carbó (nummòlt)**, you can be the first to submit a review.

ractions Scroll

Sorted Fractions

Explore Fractions, Scrolling Irreductible Fractions.

Scroll Horizontal: Swipe: From (1/n to n/1)

Scroll Vertical: Swipe: n from 4 to 80 (Maximum recommended 50)

Tool to explore sorted fractions.

Show fraction, Pie shape, squared Graph, Slope, Decimal with decimal mark.

The Fulcrum of the MathCats Balance.

Math Garden +

In this app, the natural numbers are represented as vegetables (plants):

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 th

Animated Euclidean Algorithm

Greatest Common Divisor.

Useful to reduce fractions

GCD, also known as the greatest common factor (gcf), highest common factor (hcf), greatest common measure (gcm), or highest common divisor.

Dynamic and geometric representation of the algorithm.

Recursive algorithm

And Least Common Multiple deduced from GCD:

lcm(a,b) = a*b / gcd(a,b)

Useful to understand the gcd (Euclidean Algorithm) recursive code: (Java)

int gcd(int m, int n){

if(0==n){

return m;

}else{

return gcd(n,m%n);

}

}

Added Geometric visualization.

Algorithm executed by Dandelions coming from the nearby Mathematical Garden

Euclidean Algorithm History:

("The Pulverizer")

The Euclidean algorithm is one of the oldest algorithms in common use.

It appears in Euclid's Elements (c. 300 BC), specifically in Book 7 (Propositions 1–2) and Book 10 (Propositions 2–3).

Centuries later, Euclid's algorithm was discovered independently both in India and in China, primarily to solve Diophantine equations

Create equivalent fractions by dividing and shading squares or circles, and match each fraction to its location on the number line. Check your work, and use the table feature to capture results and look for patterns. Got a particular value for which you’d like to make equivalent fractions? Use “Build Your Own” mode.

Two options for teachers:

"Settings (automatic mode)": To adjust the difficulty of the problems generated by the app.

"List sessions history": To see the last 50 right results obtained with the app.

Originally something similar to this app was developed by Illuminations, a project of the National Council of Teachers of Mathematics, and erased from the Google Play list some years ago.

It is not currently available as an online activity along with many other free math resources for teachers and students at http://illuminations.nctm.org

This is a rebuilt version from scratch dedicated to the Math Forum staff all of whom have recently lost their jobs at NCTM.

Primes as the building blocks of numbers.

THE APP:

At left: two abacuses (two numbers stacked).

At right two circles with the prime factors. (two circles with prime numbers stacked)

At right edge: all the prime numbers available to the app.

To create a number: Tap on the cells at left. The app shows the number

To add: Drag the tokens from one abacus to the other.

To subtract: Tap the sign key and drag from one abacus to the other.

To multiply: (the numbers must be previously created with the earlier previous steps)

Drag from one prime circle to the other prime circle.

To Divide a number:

Drag the prime numbers outside the prime circle:

Release prime factors to the other prime circle (integer division and multiplication)

Release prime factors between the prime circles (integer division)

Release prime factors in the list of the right edge: (integer division and erase the prime factor)

Scroll and pick a prime number from the list of the right edge:

And release it in the free zone, or in a prime circle (multiplication)

With this program you can add, subtract, multiply and divide (integer division) of any integer of any sign.

(Practically, the app is operative up to 9 digits).

(Currently, the biggest prime number available in this program is 19.874.419)

In the general menu there are 3 options:

Refresh all (erases all the tokens)

Refresh upper chart (Erases all the upper tokens)

Refresh lower chart (Erases all the lower tokens)

And a info:

The upper current available prime number.

(The app calculates new prime numbers each 20 seconds while the app is not used)

Time Calculator Place Value Time elapsed or countdown between two dates

Paid version of nummolt's Time Calculator.

Visually explains the calculations made by the free nummòlt's 'time calculator' Math Cats app.

Year, month, day, hour, minute, second ordered like any other place value system.

But time is not a usual place value system.

Each year has the same number of months: 12.

But months have a different number of days.

January, March, May, July, August,October and December have 31 days.

April, June, September and November: 30.

February has a variable number of days depending on whether is in a leap year or not.

Most years that are multiples of 4 are leap years.

Years multiples of 100 that cannot be exactly divided by 400 are not leap years.

February in a normal year has 28 days.

February in a leap year has 29 days.

The day has 24 hours.

Each hour has 60 minutes.

Each minute has 60 seconds.

I hope this visual explanation clarify any doubts that may arise.

Touch decimals:

Double interactive place value chart, with up to 40 decimal columns.

Wireless abacus.

Designed to:

- Show and experience the addition and addition with carry.

- Show and experience the subtraction and subtraction with borrowing.

- Zero as "nothing" in a place value place, or as negative-positive pairs of Tokeens or Places with sign.

Two configurations: Standard and J. LeMieux version:

Change the version, upper back arrow, or at the menu option.

S T A N D A R D . . . . C O N F I G U R A T I O N :

(Positive and negative Tokens, and Places without sign)

MAIN ELEMENTS:

Each chart with a variable number of places.

In the places, a variable number of tokens with positive or negative value

TOKENS:

A token can be positive or negative.

A positive token is born with the tap of a finger on the screen

A pair of positive-negative tokens is born with a tap of two fingers on the screen

A token disappears if it crosses the top or bottom border.

The behavior of tokens:

Positive and negative tokens have the same behavior:

A token can cross at will the intermediate horizontal border

When a token crosses the border on the right, it becomes 10 tokens.

A token need 9 companions from the old place to cross the border to the left.

Positive and negative tokens may be in the same place.

But if two tokens of different signs meet, they cancel each other.

PLACES:

A place can contain tokens of the same or different sign.

The upper and the lower borders can be the external border or the intermediate border.

Tokens can cross freely the intermediate border.

If a token cross the external border, disappears.

To get the permission to cross left borders, a token needs 9 companions of the same sign.

A token recovers 9 companions if cross the right borders.

GENERAL:

Chart:

There are two charts: The upper chart and the lower chart.

There is a button in each chart to change the sign of all its tokens.

L E . M I E U X . . . . . C O N F I G U R A T I O N :

(colored Tokens without sign, and Places with sign)

MAIN ELEMENTS:

All the Places of each chart can be positive or negative.

TOKENS:

A pair of tokens is born with a tap of two fingers on the screen over two places of different sign.

The behavior of tokens:

A token can cross at will the intermediate horizontal border if the places have the same sign.

When a Token tries to cross the border to a Place of a different sign, calls another Token of the other Place, and they cancel each other in the border.

PLACES:

A place can contain not signed colored tokens.

Tokens can cross freely the intermediate border if the sign of the two places are the same.

GENERAL:

There is a button in each chart to change the sign of all its Places.

Control:

In the 'settings' option, there is an option to erase all tokens of each chart, or to erase all tokens and refresh all to start again from scratch.

Touch decimals Place value ±

The behavior of places and tokens of this app describes the behavior of the numbers in the decimal system.

Courses:

Math 1, 2, 3, 4 Number sense: Place value.

Math 5, 6, 7 Base Ten:

** COMMON CORE State standards initiative:

**Grade 1:

Understand place value:

CCSS.MATH.CONTENT.1.NBT.B.2

Use place value understanding and properties of operations to add and subtract: CCSS.MATH.CONTENT.1.NBT.C.4; CCSS.MATH.CONTENT.1.NBT.C.5; CCSS.MATH.CONTENT.1.NBT.C.6

** Grade 2:

Place value:

CCSS.MATH.CONTENT.2.NBT.A.1

Place value understanding and properties of operations to add and subtract:

CCSS.MATH.CONTENT.2.NBT.B.5; CCSS.MATH.CONTENT.2.NBT.B.6; CCSS.MATH.CONTENT.2.NBT.B.7; CCSS.MATH.CONTENT.2.NBT.B.9

** Grade 3:

Use place value understanding and properties of operations to perform multi-digit arithmetic.

CCSS.MATH.CONTENT.3.NBT.A.2; CCSS.MATH.CONTENT.3.NBT.A.3

** Grade 4:

CCSS.MATH.CONTENT.4.NBT.B.4;

JavaScript Online version: http://www.nummolt.com/touchdecimals/index.html

Developed by: http://www.nummolt.com

Nummolt Blog: Mathematical engine mill:

http://nummolt.blogspot.com.es/2015/07/touch-decimals-chapter-i-introduction.html

Small laboratory of Natural Numbers:

The Prime numbers are the building blocks of the natural numbers.

With this app you can:

Analyze the factors of a Composite number.

Build a Composite number from its factors. (multiplication and division of Natural Numbers)

Localize or select a number in the Ulam Spiral.

(Only the Prime Numbers have a color in this spiral).

Verify all the possible products between Primes in a composite number with the Parabolic Sieve.

Analyze or build a number with the Place Value activity (Addition and Subtraction of Natural Numbers)

Understanding the Modulo of a number.

Know about the polygonal numbers and the numbers as the sum of two prime numbers, and as the sum of three Prime Numbers.

[Android native app]

The free app Adding unit fractions proposes 21 challenges to overcome.

Obtaining the proper fractions listed at the top of the application, adding two or three unit fractions. (four in the + version)

Each proposed proper faction has a variable number of solutions.

And different levels of difficulty

You can not repeat unit fractions with the same value.

In the options you'll find a button to delete all the solutions found in the current problem, and to start from scratch.

The littlest unit fraction used in this app is 1/28.

There's a similar app named Adding unit fractions plus.

Contains more challenging problems.

Adding unit fractions plus is a paid app.

[Android native app]

Basic tool for to experiment with fractions:

The app lets you view the fractions represented in the form of overlapping circles and bars.

The two graphs are interactive. They can be changed by dragging on the screen.

Graphically, fractions are always shown in simplified form.

There are two spinners to select fractions: one for the numerator and one for the denominator.

At the right there are two lock buttons:

The top button locks the numerator when the graph is modified.

The lower button locks the denominator when the graph is modified.

When both buttons are unlocked, the fractions are formed from the denominator 360 (the maximum allowed in the program) when the graph is modified.

When the two buttons are locked, the program always remains under the same fraction, but expresses its equivalent fractions in the spinners.

When the fraction expressed in the spinners is not in its simplified form, can be simplified by clicking on the simplified expression on his left.

Additionally fractions are shown in written words, mixed fractions (if needed) as a percentage and as a decimal number with dot.

Fractions in words: Available in English, Catalan, Castilian (spanish), French and Portuguese

[Android native app]

Balance items ranging from electrons to galaxies.

Balance them, multiplying or dividing each one.

App made in a collaboration: www.mathcats.com - www.nummolt.com

Based in the original: http://www.mathcats.com/explore/balance/balance.html

(same authors)

The Android version is near a true balance scale: It balances.

In ancient Egypt, they wrote fractions with numerator 1 or as a sum of fractions with numerator 1. So the fraction 2/3 would be 1/2 +1 / 6. It has a certain logic if we consider a particular case: if we divide two loaves among three people will give each bread half (1/2) and a third of the bread is left half (1/6).

[Android native app, but HTML + javascript based. Using WebView]

Calculator in the set of the natural numbers (ℕ)

When the result leaves the set of natural numbers, this calculator points to the need of to upgrade to a calculator with more features. ( ℤ calculator or ℚ calculator).

Type the numerical operations and results in words.

Write properly until the centillion.

Purpose: Educational resource.

Developed for the Double Struck Capital Project.

[Android native app]

Elapsed / Countdown Time Calculator

With the Time Calculator you can calculate the subtraction between 2 dates:

You can fix a date in the past and subtract it from the present time: You get the elapsed time.

You can fix a date in the future and subtract the present time: You get the countdown to the fixed date.

Version 1.2.0 Saves last configuration in the device (2015-04-23).

This is the version 1.1.4 r10.

Here definitively abandoning the use of Apache Cordova for this program.

The Android WebView has been much easier to use.

[Android native app, but HTML + Javascript based. Using WebView]

The game is about to find solutions ordering the numbers from 1 to 9 in a square of 3 * 3 where the sum of the numbers of the two top rows is equal to the bottom row.

Ninedigits has 336 solutions. If the program would be easy for someone, then the goal could be to find valid solutions in which a lady could travel chess boxes 1 to 9 making right moves to this tab. According to our analysis, there are 3 solutions of this type. You can also look under the same condition, but with the tower of chess. This combination of conditions has only one solution. The program clearly shows the production of these special results.

[Apache Cordova 3.6.3 app. Updated by request of Google (Security issues early versions of apache cordova)]

Solving a system of linear equations with two equations and two unknown variables. (Two purchases of fruits)

With 5 tools to solve the problem.

Gauss-Jordan elimination

Crossing lines

Weighing scales (substitution)

Cramer's Rule

Inverse matrix

[Android native app]

Review and locate the Josep Maria Jujol main architectural works:

Casa Bofarull Els Pallaresos.

Església del Sagrat Cor de Vistabella

Teatre del Patronat Obrer de Tarragona

Casa Ximenis de Tarragona

Can Negre de Sant Joan Despí

Casa Sansalvador de Barcelona

Casa Planells de Barcelona

......

[Android native app]

Description

The mechanism :

The green outer ring with 5 primary partitions and and 300 smaller partitions gives 59/300 turns per minute counterclockwise: 11.8 turns per hour.

The planetary gear of the seconds, in green color, is driven by the outer ring and gives 59 rph counterclockwise. And in turn, the axis makes a complete turn clockwise, rolling on the inside of the crown of the minutes, by hour.

The hand of the minutes, in blue color, turning on the central axis and linked to the axis of the planetary gear of the seconds, makes a complete turn every hour.

The wheel that rotates clockwise integrally with its base and with the hand of the minutes, make to spin counterclockwise two blue planetary wheels. These two planetary wheels spins counterclockwise a third planetary gear.

The third planetary wheel rotates one turn per hour clockwise and transmits the rotation to the fourth planetary wheel. The fourth planetary wheel spins counterclockwise and progresses clockwise.

The fourth blue planetary wheel gives 2 turns on itself and its axis gives the entire turn around the sphere of the clock every 12 hours.

On the four planetary wheels is mounted the hour hand: a big red triangle, giving rigidity to the structure and indicating the hours and rotating clockwise.

The big red triangle, linked to a freewheel on the central axis, drives the rotation of the three static planetary yellow wheels of the day. Turning counterclockwise about its fixed axis, rotates counterclockwise the yellow big crown that distinguishes the day light hours, of the darkness of the night and makes a complete turn every 24 hours.

The big red triangle, also linked to another freewheel on the central axis, drives the rotation of three static planetary wheels magenta of the week, much bigger than those for the day. Turning counterclockwise about its fixed axis, and spinning counterclockwise the crown magenta indicating the day of the week, and makes a complete turn every week.

Interaction:

Buttons:

The buttons are used to toggle the different layers of the watch:

Blue hand of minutes, and the green planetary gear of the seconds

Green crown of the seconds.

Static blue sphere of the hours and the minutes.

Planetary gear set and red triangle of the hours.

Planetary gear set in yellow color, and yellow crown of the day and the night

Planetary gear set in magenta color, and yellow crown of weekday.

Clock base body.

Dragging:

Dragging a finger, you can move the clock from its initial position.

Joining or separating and sliding two fingers on the screen, reduce or increase the size of the watch.

Dragging and rotating about the central axis with the finger on the red triangle of the hours, you can change the time. After removing the finger, the 'circadian clock', will slowly readjusting to redial the actual system time.

Circadian Clock:

www.nummolt.com

Note from developer:

The term 'circadian' comes from the Latin 'circa', meaning "around" (or "approximately"), and 'diem' or 'dies', meaning "day".

This app is only a clock, with many layers, showing many overlapped mechanisms, with zoom. The triangle of the hours is manually adjustable, and has an algorithm to reset the clock to the system time after any adjustment.

Nothing concerning the biological circadian cycle.

But one of the layers of the clock represents daylight.

[Android native app]

24 hours clock app + live wallpaper (Eternity Fragments)

Time in UTC (Internet Time)

Local hour (one hand)

Antartic rotation.

Earth shadow.

Based in the Carles Mamano blueprints (1999).

© 1999-2014 Carles Mamano, Architect.

App developed by nummolt. (1 week)

Barcelona June 2014

[Android native app]

Adding unit fractions is based in my old javascript + applets: "Old Egyptian Fractions" made in collaboration http://www.mathcats.com (Wendy Petti) and http://www.nummolt.com (myself)

The feature graphic of Adding unit fractions recalls the origins of the program.

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