<?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>2448-8089</journal-id>
<journal-title><![CDATA[Educación matemática]]></journal-title>
<abbrev-journal-title><![CDATA[Educ. mat.]]></abbrev-journal-title>
<issn>2448-8089</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de Investigación y Divulgación de la Educación Matemática A.C.; Universidad de Guadalajara]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S2448-80892018000300122</article-id>
<article-id pub-id-type="doi">10.24844/em3003.06</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Estrategias de cálculo mental para sumas y restas desarrolladas por estudiantes de secundaria]]></article-title>
<article-title xml:lang="en"><![CDATA[Mental calculation strategies for addition and subtraction developed by middle school students]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Barrera-Mora]]></surname>
<given-names><![CDATA[Fernando]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Reyes-Rodríguez]]></surname>
<given-names><![CDATA[Aarón]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Mendoza-Hernández]]></surname>
<given-names><![CDATA[José Guadalupe]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad Autónoma del Estado de Hidalgo Área Académica de Matemáticas y Física ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad Autónoma del Estado de Hidalgo Área Académica de Matemáticas y Física ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,Universidad Autónoma del Estado de Hidalgo Área Académica de Matemáticas y Física ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>00</month>
<year>2018</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>00</month>
<year>2018</year>
</pub-date>
<volume>30</volume>
<numero>3</numero>
<fpage>122</fpage>
<lpage>150</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S2448-80892018000300122&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S2448-80892018000300122&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S2448-80892018000300122&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen: Las estrategias de cálculo mental juegan un rol importante en el desarrollo del sentido numérico. Al respecto, buscamos determinar cómo alumnos de una telesecundaria, ubicada en una comunidad rural del estado de Hidalgo, México, pueden desarrollar estrategias de cálculo mental al realizar tareas que involucran sumas y restas en contextos de compraventa. Identificamos ocho estrategias diferentes, algunas de las cuales emplearon el dinero de fantasía como sistema de representación, que apoyó la descomposición de las cantidades en forma novedosa. Los estudiantes hicieron referencia a estrategias que utilizan personas sin escolaridad al recibir el cambio de compras en el mercado; también aparecieron estrategias como quitar uno al minuendo en una resta con reagrupación, para obtener una sin reagrupación. Esto es, se observó una transferencia de las estrategias de cálculo mental, cuando los participantes modificaron el algoritmo estándar para la resta, con el objetivo de facilitar los cálculos al resolver un problema. Esto es un indicador de creatividad y entendimiento de los números y las operaciones.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract: Mental calculation strategies play an important role in the development of students&#8217; number sense. In this regard, we sought to determine how students of a public middle school (distance education program), located in a rural community in the state of Hidalgo, Mexico, can develop mental calculation strategies when performing tasks involving addition and subtraction, in a shopping context. Eight different strategies were identified, some of which used fantasy money as a representation system that helped students to decompose quantities. They referred to strategies used by people, without schooling, when they receiving money back after paying for a purchase in the market. Strategies such as removing one to the minuend in a subtraction with regrouping also appeared, to obtain one addition without regrouping. That is, we identified a transfer of mental calculation strategies to paper and pencil scenarios, which facilitate calculations to solve a problem. This is an indicator of creativity and understanding of numbers and operations.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[sentido numérico]]></kwd>
<kwd lng="es"><![CDATA[cálculo mental]]></kwd>
<kwd lng="es"><![CDATA[suma y resta]]></kwd>
<kwd lng="es"><![CDATA[compraventa]]></kwd>
<kwd lng="en"><![CDATA[number sense]]></kwd>
<kwd lng="en"><![CDATA[mental calculation]]></kwd>
<kwd lng="en"><![CDATA[addition and subtraction]]></kwd>
<kwd lng="en"><![CDATA[tasks in a shopping context]]></kwd>
</kwd-group>
</article-meta>
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