{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T06:03:45Z","timestamp":1789625025590,"version":"build-2803163510"},"reference-count":58,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Psychol."],"abstract":"<jats:p>Mathematical learning difficulties (MLD) are estimated to affect a substantial proportion of children worldwide, yet psychometrically validated screening instruments for early numerical development remain scarce in non-WEIRD countries, including Brazil. MARKO-Screening is a brief, theoretically grounded screening instrument designed to assess early numerical development in preschool and early elementary children. Based on a developmental trajectory model of numerical concept acquisition, MARKO-S evaluates foundational concepts including counting, ordinality, and cardinality. This study aimed to adapt and validate a Brazilian Portuguese version of MARKO-S (MARKO-S BR) for early identification of children at risk for MLD, examining evidence of content validity, internal structure, and relations with other variables in a sample of 1,200 children from preschool to second grade, enrolled in public and private schools across three Brazilian regions. Results provided evidence of structural validity, with item difficulty largely aligned with the theoretical model, and convergent validity through positive correlations with established mathematical assessments. MARKO-S BR scores showed significant grade-related differences, consistent with the expected acquisition of numerical concepts across schooling. Substantial performance gaps also emerged between public and private school students, reflecting systemic inequalities in early mathematics education in Brazil. These findings support MARKO-S BR as a psychometrically sound, culturally adapted screening instrument, addressing the scarcity of validated early mathematics assessments and providing Brazilian educators and clinicians with an evidence-based digital tool for early identification of children at risk for MLD.<\/jats:p>","DOI":"10.3389\/fpsyg.2026.1794101","type":"journal-article","created":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T05:32:13Z","timestamp":1789623133000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Screening early numerical development in Brazilian children: adaptation and validation of MARKO-S"],"prefix":"10.3389","volume":"17","author":[{"given":"Fernanda Rocha","family":"de Freitas","sequence":"first","affiliation":[{"name":"Department of Psychology, Universidade Federal de Minas Gerais","place":["Belo Horizonte, Brazil"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Moritz","family":"Herzog","sequence":"additional","affiliation":[{"name":"Institute for Mathematics Education, University of Cologne","place":["Cologne, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariuche","family":"Gomides","sequence":"additional","affiliation":[{"name":"Department of Psychology, Universidade Federal de Minas Gerais","place":["Belo Horizonte, Brazil"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antje","family":"Ehlert","sequence":"additional","affiliation":[{"name":"Institute for Inclusive Education, University of Potsdam","place":["Potsdam, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annemarie","family":"Fritz","sequence":"additional","affiliation":[{"name":"Akademie Wort + Zahl","place":["Cologne, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vitor Geraldi","family":"Haase","sequence":"additional","affiliation":[{"name":"Department of Psychology, Universidade Federal de Minas Gerais","place":["Belo Horizonte, Brazil"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,17]]},"reference":[{"key":"ref1","volume-title":"Standards for Educational and Psychological Testing","year":"2014"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"e0259331","DOI":"10.1371\/journal.pone.0259331","article-title":"Money matters (especially if you are good at math): numeracy, verbal intelligence, education, and income in satisfaction judgments","volume":"16","author":"Bj\u00e4lkebring","year":"2021","journal-title":"PLoS One"},{"key":"ref3","doi-asserted-by":"crossref","DOI":"10.4324\/9780429030499","volume-title":"Applying the Rasch Model: Fundamental Measurement in the Human Sciences","author":"Bond","year":"2020"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"1337716","DOI":"10.3389\/feduc.2024.1337716","article-title":"Exploring the potential of a game-based preschool assessment of mathematical competencies","volume":"9","author":"Chatzaki","year":"2024","journal-title":"Front. Educ."},{"key":"ref5","volume-title":"Assessing Student Proficiency of Number sense (ASPENS)","author":"Clarke","year":"2011"},{"key":"ref6","doi-asserted-by":"crossref","DOI":"10.4324\/9780203520574","volume-title":"Learning and Teaching Early Math: The Learning Trajectories Approach","author":"Clements","year":"2014"},{"key":"ref7","volume-title":"Mathematik- und Rechenkonzepte im Vorschulalter \u2013 Screening","author":"Ehlert","year":"2020"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"127","DOI":"10.1002\/(SICI)1520-6807(199804)35:2<>3.0.CO;2-M","article-title":"Reliability and validity of the math essential skill screener?Elementary version (MESS-E)","volume":"35","author":"Erford","year":"1998","journal-title":"Psychol. Sch."},{"key":"ref9","doi-asserted-by":"publisher","first-page":"108","DOI":"10.1027\/2698-1866\/a000102","article-title":"Adaptation and validation in Spanish of the MARKO-D test for the assessment of initial mathematical concepts","volume":"6","author":"Espinoza","year":"2025","journal-title":"Psychol. Test Adapt. Dev."},{"key":"ref10","doi-asserted-by":"publisher","first-page":"38","DOI":"10.4102\/sajce.v3i1.31","article-title":"Development of mathematical concepts as basis for an elaborated mathematical understanding","volume":"3","author":"Fritz","year":"2013","journal-title":"S. Afr. J. Child. Educ."},{"key":"ref11","doi-asserted-by":"publisher","first-page":"7","DOI":"10.1007\/s13138-018-0131-6","article-title":"Arithmetische Konzepte aus kognitiv-entwicklungspsychologischer Sicht","volume":"39","author":"Fritz","year":"2018","journal-title":"J. Math.-Didakt."},{"key":"ref12","doi-asserted-by":"publisher","first-page":"206","DOI":"10.1037\/a0025398","article-title":"Mathematical cognition deficits in children with learning disabilities and persistent low achievement: a five-year prospective study","volume":"104","author":"Geary","year":"2012","journal-title":"J. Educ. Psychol."},{"key":"ref13","doi-asserted-by":"publisher","first-page":"256","DOI":"10.1037\/edu0000277","article-title":"Predicting age of becoming a cardinal principle knower","volume":"111","author":"Geary","year":"2019","journal-title":"J. Educ. Psychol."},{"key":"ref14","volume-title":"The Child\u2019s Understanding of Number","author":"Gelman","year":"1978"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"423","DOI":"10.1177\/001440291207800403","article-title":"Universal screening in mathematics for the primary grades: beginnings of a research base","volume":"78","author":"Gersten","year":"2012","journal-title":"Except. Child."},{"key":"ref16","volume-title":"Test of Early Mathematics Ability (TEMA-3)","author":"Ginsburg","year":"2003"},{"key":"ref17","volume-title":"PRONUMERO - Bateria de avalia\u00e7\u00e3o do processamento num\u00e9rico e c\u00e1lculo","author":"Gomides","year":""},{"key":"ref18","doi-asserted-by":"publisher","first-page":"267","DOI":"10.1590\/1980-57642021dn15-020015","article-title":"The quandary of diagnosing mathematical difficulties in a generally low performing population","volume":"15","author":"Gomides","year":"","journal-title":"Dement. Neuropsychol."},{"key":"ref19","first-page":"101","article-title":"Arithmetische Konzepte am Schulanfang im Deutschen \u2013 und im T\u00fcrkischen? Eine empirische Studie zu gesamtsprachlichen Mathematikleistungen von deutsch- und t\u00fcrkischsprachigen Grundschulkindern","volume-title":"Deutsch als Zweitsprache: Perspektiven auf Schule und Hochschule, Erwerb und Didaktik","author":"G\u00fcrsoy","year":"2020"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"407","DOI":"10.1007\/s11858-019-01106-z","article-title":"Health and numeracy: the role of numeracy skills in health satisfaction and health-related behaviour","volume":"52","author":"Heilmann","year":"2020","journal-title":"ZDM"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"1","DOI":"10.15700\/saje.v41n4a1979","article-title":"Development of an instrument to assess early number concept development in four south African languages","volume":"41","author":"Henning","year":"2021","journal-title":"S. Afr. J. Educ."},{"key":"ref22","volume-title":"ITC Guidelines for the Adaptation of Tests","year":"2017"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"582","DOI":"10.1080\/02796015.2007.12087919","article-title":"Screening for at-risk readers in a response to intervention framework","volume":"36","author":"Jenkins","year":"2007","journal-title":"Sch. Psychol. Rev."},{"key":"ref24","doi-asserted-by":"publisher","first-page":"181","DOI":"10.1080\/02796015.2010.12087772","article-title":"Validating a number sense screening tool for use in kindergarten and first grade: prediction of mathematics proficiency in third grade","volume":"39","author":"Jordan","year":"2010","journal-title":"Sch. Psychol. Rev."},{"key":"ref9001","first-page":"152","article-title":"A critique of Rasch residual fit statistics","volume":"1","author":"Karabatsos","year":"2000","journal-title":"Journal of Applied Measurement"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"24","DOI":"10.11114\/jets.v7i2.3888","article-title":"Validity and reliability study for the Turkish version of number sense screener for 60-71 months old children","volume":"7","author":"K\u0131z\u0131ltepe","year":"2018","journal-title":"J. Educ. Train. Stud."},{"key":"ref26","doi-asserted-by":"publisher","first-page":"383","DOI":"10.17105\/SPR-2018-0084.V48-4","article-title":"Improving mathematics screening in middle school","volume":"48","author":"Klingbeil","year":"2019","journal-title":"Sch. Psychol. Rev."},{"key":"ref27","doi-asserted-by":"publisher","first-page":"e249592","DOI":"10.1590\/es.249592_in","article-title":"Home learning environment and cognitive development during early childhood education","volume":"43","author":"Koslinski","year":"2022","journal-title":"Educ. Soc."},{"key":"ref28","doi-asserted-by":"publisher","first-page":"513","DOI":"10.1016\/j.learninstruc.2008.10.002","article-title":"Early development of quantity to number-word linkage as a precursor of mathematical school achievement and mathematical difficulties: findings from a four-year longitudinal study","volume":"19","author":"Krajewski","year":"2009","journal-title":"Learn. Instr."},{"key":"ref29","doi-asserted-by":"publisher","first-page":"791","DOI":"10.1037\/dev0002099","article-title":"The role of children\u2019s finger counting history on their addition skills","volume":"62","author":"Krenger","year":"2025","journal-title":"Dev. Psychol."},{"key":"ref31","first-page":"878","article-title":"What do infit and outfit, mean-square and standardized mean?","volume":"16","author":"Linacre","year":"2002","journal-title":"Rasch Meas. Trans."},{"key":"ref32","volume-title":"Winsteps\u00ae Rasch Measurement Computer program (Version 5.10.4)","author":"Linacre","year":"2025"},{"key":"ref30","doi-asserted-by":"publisher","first-page":"1035","DOI":"10.3389\/fpsyg.2018.01035","article-title":"Children\u2019s non-symbolic and symbolic numerical representations and their associations with mathematical ability","volume":"9","author":"Li","year":"2018","journal-title":"Front. Psychol."},{"key":"ref33","doi-asserted-by":"publisher","first-page":"714","DOI":"10.1111\/desc.12152","article-title":"Numerical predictors of arithmetic success in grades 1\u20136","volume":"17","author":"Lyons","year":"2014","journal-title":"Dev. Sci."},{"key":"ref34","doi-asserted-by":"publisher","first-page":"486","DOI":"10.3389\/fpsyg.2013.00486","article-title":"Persistent consequences of atypical early number concepts","volume":"4","author":"Mazzocco","year":"2013","journal-title":"Front. Psychol."},{"key":"ref35","doi-asserted-by":"publisher","first-page":"1727","DOI":"10.3389\/fpsyg.2016.01727","article-title":"Policy implications of achievement testing using multilevel models: the case of Brazilian elementary schools","volume":"7","author":"Menezes","year":"2016","journal-title":"Front. Psychol."},{"key":"ref36","doi-asserted-by":"publisher","first-page":"88","DOI":"10.1093\/arclin\/acu071","article-title":"From \u201cfive\u201d to 5 for 5 minutes: Arabic number transcoding as a short, specific, and sensitive screening tool for mathematics learning difficulties","volume":"30","author":"Moura","year":"2015","journal-title":"Arch. Clin. Neuropsychol."},{"key":"ref37","doi-asserted-by":"publisher","first-page":"e42483","DOI":"10.2196\/42483","article-title":"The digital divide in Brazil and barriers to telehealth and equal digital health care: analysis of internet access using publicly available data","volume":"25","author":"Nakayama","year":"2023","journal-title":"J. Med. Internet Res."},{"key":"ref38","doi-asserted-by":"publisher","first-page":"e67918","DOI":"10.1371\/journal.pone.0067918","article-title":"A two-minute paper-and-pencil test of symbolic and nonsymbolic numerical magnitude processing explains variability in primary school children\u2019s arithmetic competence","volume":"8","author":"Nosworthy","year":"2013","journal-title":"PLoS One"},{"key":"ref39","volume-title":"Pesquisa sobre o uso da internet por crian\u00e7as e adolescentes no Brasil: TIC Kids Online Brasil 2023 [Livro eletr\u00f4nico]","year":"2024"},{"key":"ref40","volume-title":"PISA 2022 Results (Volume I): The State of Learning and Equity in Education","year":"2023"},{"key":"ref41","doi-asserted-by":"publisher","first-page":"110","DOI":"10.1007\/s10648-024-09950-6","article-title":"Measuring mathematical skills in early childhood: a systematic review of the psychometric properties of early maths assessments and screeners","volume":"36","author":"Outhwaite","year":"2024","journal-title":"Educ. Psychol. Rev."},{"key":"ref42","volume-title":"Matrizes progressivas coloridas de Raven","author":"Paula","year":"2018"},{"key":"ref43","doi-asserted-by":"publisher","first-page":"41","DOI":"10.17105\/SPR44-1.41-59","article-title":"Using a brief preschool early numeracy skills screener to identify young children with mathematics difficulties","volume":"44","author":"Purpura","year":"2015","journal-title":"Sch. Psychol. Rev."},{"key":"ref9002","volume-title":"Probabilistic Models for Some Intelligence and Attainment Tests","author":"Rasch","year":"1960"},{"key":"ref44","volume-title":"R: A Language and Environment for Statistical Computing","year":"2026"},{"key":"ref45","doi-asserted-by":"publisher","first-page":"rm1","DOI":"10.1187\/cbe.15-08-0183","article-title":"Contemporary test validity in theory and practice: a primer for discipline-based education researchers","volume":"15","author":"Reeves","year":"2016","journal-title":"CBE Life Sci. Educ."},{"key":"ref46","doi-asserted-by":"crossref","first-page":"675","DOI":"10.1002\/9781118489772.ch22","volume-title":"The Wiley Handbook of Psychometric Testing: A Multidisciplinary Reference on Survey, scale and test Development","author":"Reise","year":"2018"},{"key":"ref47","volume-title":"Mathematik- und Rechen konzepte im Vorschulaltet\u2014Diagnose","author":"Ricken","year":"2013"},{"key":"ref48","doi-asserted-by":"publisher","first-page":"137","DOI":"10.1037\/met0000045","article-title":"Evaluating bifactor models: calculating and interpreting statistical indices","volume":"21","author":"Rodriguez","year":"2016","journal-title":"Psychol. Methods"},{"key":"ref49","doi-asserted-by":"publisher","first-page":"513","DOI":"10.5209\/rev_SJOP.2012.v15.n2.38862","article-title":"Number processing and calculation in Brazilian children aged 7-12 years","volume":"15","author":"Santos","year":"2012","journal-title":"Span. J. Psychol."},{"key":"ref50","first-page":"205","article-title":"Detecting and evaluating the impact of multidimensionality using item fit statistics and principal component analysis of residuals","volume":"3","author":"Smith","year":"2002","journal-title":"J. Appl. Meas."},{"key":"ref51","doi-asserted-by":"publisher","first-page":"32","DOI":"10.1111\/emip.12536","article-title":"Psychometric evaluation of the preschool early numeracy skills test\u2013brief version within the item response theory framework","volume":"42","author":"Tsigilis","year":"2023","journal-title":"Educ. Meas. Issues Pract."},{"key":"ref52","year":"2025"},{"key":"ref53","doi-asserted-by":"publisher","first-page":"155","DOI":"10.1177\/1476718X030012002","article-title":"The development of early numeracy in Europe","volume":"1","author":"Van De Rijt","year":"2003","journal-title":"J. Early Child. Res."},{"key":"ref54","doi-asserted-by":"publisher","first-page":"39","DOI":"10.1186\/s41155-016-0045-5","article-title":"Development of the arithmetic subtest of the school achievement test-second edition","volume":"29","author":"Viapiana","year":"2016","journal-title":"Psicologia: Reflex\u00e3o e Cr\u00edtica"},{"key":"ref55","doi-asserted-by":"publisher","first-page":"2332858420928985","DOI":"10.1177\/2332858420928985","article-title":"Academic achievement and economic attainment: reexamining associations between test scores and long-run earnings","volume":"6","author":"Watts","year":"2020","journal-title":"AERA Open"},{"key":"ref56","doi-asserted-by":"publisher","first-page":"352","DOI":"10.3102\/0013189X14553660","article-title":"What\u2019s past is prologue: relations between early mathematics knowledge and high school achievement","volume":"43","author":"Watts","year":"2014","journal-title":"Educ. Res."}],"container-title":["Frontiers in Psychology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpsyg.2026.1794101\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T05:32:18Z","timestamp":1789623138000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpsyg.2026.1794101\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,17]]},"references-count":58,"alternative-id":["10.3389\/fpsyg.2026.1794101"],"URL":"https:\/\/doi.org\/10.3389\/fpsyg.2026.1794101","relation":{},"ISSN":["1664-1078"],"issn-type":[{"value":"1664-1078","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,17]]},"article-number":"1794101"}}