Materials count: Linear-spatial materials improve young children’s addition strategies and accuracy, irregular arrays don’t

• Joanna Schiffman ,

  Roles Conceptualization, Formal analysis, Methodology, Project administration, Writing – original draft, Writing – review & editing

  * E-mail: joanna.schiffman@bc.edu

  Affiliation Department of Counseling, Developmental, and Educational Psychology, Boston College, Chestnut Hill, Massachusetts, United States of America

  http://orcid.org/0000-0002-8959-003X

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• Elida V. Laski

  Roles Conceptualization, Methodology, Resources, Supervision, Writing – original draft, Writing – review & editing

  Affiliation Department of Counseling, Developmental, and Educational Psychology, Boston College, Chestnut Hill, Massachusetts, United States of America

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