<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1659-0643</journal-id>
<journal-title><![CDATA[Revista Digital: Matemática, Educación e Internet]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. Dig. Mat. Educ. Internet]]></abbrev-journal-title>
<issn>1659-0643</issn>
<publisher>
<publisher-name><![CDATA[Instituto Tecnológico de Costa Rica]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1659-06432024000100002</article-id>
<article-id pub-id-type="doi">10.18845/rdmei.v24i1.6777</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Principios matemáticos, nutricionales y didácticos del uso de ecuaciones 3 × 3 con Excel en la formulación de alimentos balanceados y de raciones para animales]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Santana Pérez]]></surname>
<given-names><![CDATA[Angel Arturo]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Zamora Regueiro]]></surname>
<given-names><![CDATA[Carlos]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Aroche Ginarte]]></surname>
<given-names><![CDATA[Roisbel]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Verdecia Acosta]]></surname>
<given-names><![CDATA[Danis Manuel]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Ramírez de la Ribera]]></surname>
<given-names><![CDATA[Jorge Luis]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad de Granma. Grama  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Cuba</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad de Granma. Grama  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Cuba</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,Universidad de Granma. Grama  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Cuba</country>
</aff>
<aff id="Af5">
<institution><![CDATA[,Universidad de Granma. Grama  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Cuba</country>
</aff>
<aff id="Af6">
<institution><![CDATA[,Universidad de Granma. Grama, Cuba  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Cuba</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>02</month>
<year>2024</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>02</month>
<year>2024</year>
</pub-date>
<volume>24</volume>
<numero>1</numero>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_arttext&amp;pid=S1659-06432024000100002&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_abstract&amp;pid=S1659-06432024000100002&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_pdf&amp;pid=S1659-06432024000100002&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen El empleo de diferentes métodos matemáticos en la formulación de raciones y de alimentos balanceados para animales exige el domino simultáneo de principios matemáticos, de nutrición animal y también de habilidades didácticas para su enseñanza en los instituciones donde se estudian carreras agropecuarias. El presente artículo tiene como objetivo mostrar cómo integrar tales pericias, específicamente en el uso de ecuaciones    3 × 3  y motivar el uso del Excel para todos estos fines. Desde el punto de vista nutricional se describe cómo considerar las particularidades del valor nutritivo de cada alimento en el planteamiento de las ecuaciones iniciales para lograr los ajustes de las cantidades y/o proporciones de tres nutrientes aportados por ellos a los respectivos requerimientos nutricionales de los animales. Matemáticamente se muestran las posibilidades de estos sistemas de ecuaciones    3 × 3  y del uso correcto de las unidades de medida para resolver problemas de formulación de dietas animales, cómo plantearlos e implementarlos en Excel por los profesionales vinculados a la alimentación de los animales. Didácticamente se hace un aporte importante pues se muestran dos ejemplos de problemas prácticos y reales para que sean usados en la enseñanza de los sistemas de ecuaciones    3 × 3  en otros tipos de enseñanza también.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract The use of different mathematical methods during the process of animal ration and concentrates formulation demands integral skills on animal nutrition, mathematics and didactical abilities during teaching of such methods at the institutions where agricultural careers are taught. This article aims to demonstrate how to integrate such capabilities, specifically on the use of    3 × 3  equations and to motivate using Excel for that purpose. From the nutritional point of view, it is described how to consider the exactitudes on the nutritive value of each feed in    3 × 3  system of equations in order to fit the amount and/or proportion of three nutrients to their animal requirements. It was also demonstrated the mathematical possibilities of   3 × 3  system of equations to solve diet formulation for animals, how to formulate them with Excel by those dealing with animal feeding. Didactically, it was noticeable that two examples of real and practical problems for teaching    3 × 3  systems of equations were given.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[sistemas de ecuaciones 3x3]]></kwd>
<kwd lng="es"><![CDATA[matrices]]></kwd>
<kwd lng="es"><![CDATA[alimentación animal]]></kwd>
<kwd lng="en"><![CDATA[3x3 system of equations]]></kwd>
<kwd lng="en"><![CDATA[matrix]]></kwd>
<kwd lng="en"><![CDATA[animal feeding]]></kwd>
</kwd-group>
</article-meta>
</front><back>
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