《义务教育课程方案和课程标准（2022版）》的颁布，意味着核心素养已成为引领基础教育阶段教学改革的灵魂要素，核心素养离不开知识，知识离不开学科，学科核心素养的出台倒逼教学设计的变革，教学设计要从设计一个知识点或课时转变为设计一个大单元，核心素养的落实呼唤大单元教学设计。科学教育是全面提高学生科学核心素养、培育具备科学家潜质的青少年群体的重要手段。近年来，教育部等部门出台一系列举措，推进科学教育落地生根。加强科学教育，是时代所需，基础教育阶段的科学教育质量对提高学生的科学核心素养至关重要。
大单元教学是落实学科核心素养的重要路径，目前大单元教学尚处于初步探索的阶段，关于科学学科的大单元教学案例尤其少。基于此，本研究者利用在一所小学进行教学实践的机会，结合本专业学习，开展小学科学大单元教学设计与实践研究。研究围绕“基于学科核心素养的小学科学大单元教学设计框架是怎样的？”“如何根据基于学科核心素养的小学科学大单元教学设计框架开发课程案例？”以及“实施大单元后的教学效果如何？对学生科学核心素养的发展是否具有促进作用？”三个问题展开。
本研究在文献梳理的基础之上，结合相关理论汲取，首先确立小学科学大单元教学设计原则和构建基于学科核心素养的小学科学大单元教学设计框架，并以此框架为指导，以课程标准为主要依据，选择教科版五年级上册《计量时间》单元的相关内容，进行大单元教学设计与教学实践，并设计了多种追踪学生科学核心素养的评价工具，如实验记录单、单元记录单等。为检验大单元教学效果，本研究通过实验研究法和调查研究法，在实习学校开展了为期四周的小学科学“计量时间”大单元教学实践，采用课堂观察、问卷调查、访谈等方式收集数据并进行定性和定量的数据分析，从科学核心素养的四个维度即科学观念、科学思维、探究实践、态度责任四个维度进行问卷调查，从大单元教学的整体满意度、收获与建议等方面对部分学生进行访谈。
本研究发现：（1）基于学科核心素养的小学科学大单元教学设计框架能够有效指导小学科学教学设计，“计量时间”大单元教学设计资源和具体操作路径，对旨在培养学生科学核心素养的大单元教学设计提供了更具体的指导和案例说明。（2）在此框架指导下设计和实施的“计量时间”大单元教学能够显著提升学生科学核心素养的发展水平，其较常规单元教学更有优势。

The promulgation of Compulsory Education Curriculum Program and Curriculum Standards (2022 Edition) means that core literacy has become the soul element leading the teaching reform in the basic education stage. Core literacy cannot be separated from knowledge, and knowledge cannot be separated from disciplines. The introduction of core literacy in disciplines forces the reform of teaching design. Teaching design should change from designing a knowledge point or class time to designing a large unit. The implementation of core literacy calls for large-unit teaching design. Science education is an important means to comprehensively improve students' core scientific literacy and cultivate young people with the potential of scientists. In recent years, the Ministry of Education and other departments have introduced a series of measures to promote the implementation of science education. Strengthening science education is needed by the times. The quality of science education in basic education stage is crucial to improving students' core scientific literacy.
Large unit teaching is an important path to implement core competencies in the discipline. Currently, it is still in the initial exploration stage, and there are particularly few cases of large unit teaching in science subjects. Based on this, the author takes advantage of the opportunity to conduct teaching practice in a primary school, combined with the study of their major, to carry out research on the design and practice of primary school science unit teaching. The research centers on three questions: "What is the teaching design framework of primary science large units based on core literacy?" "How to develop curriculum cases according to the teaching design framework of primary science large units based on core literacy?" and "What is the teaching effect after the implementation of large units? Does it have a promoting effect on the development of students' core scientific literacy?".
Based on literature review and relevant theories, this paper firstly established the teaching design principles of primary science large unit and the teaching design framework of primary science large unit based on the core literacy of the subject. With this framework as the guide, taking the curriculum standards as the main basis, the relevant content of the "measuring time" unit in the first volume of the fifth grade of the textbook was selected to carry out the teaching design and teaching practice of the large unit, and designed a variety of evaluation tools to track students' core literacy of science, such as experimental record sheet, unit record sheet, etc. In order to test the teaching effect of the large unit, this paper carried out a four-week teaching practice of the "measuring time" large unit of primary science in the internship school through experimental research method and investigation method. During the implementation process, data was collected through classroom observations, questionnaires, and interviews, followed by qualitative and quantitative analyses of the data. A questionnaire survey was conducted based on the four dimensions of scientific core literacy, namely scientific concepts, scientific thinking, inquiry practices, and attitudes and responsibilities. Additionally, interviews were held with a portion of students to gather their overall satisfaction, gains, and suggestions regarding the large-unit teaching approach.
The research found that: (1) The teaching design framework of primary school science large-unit based on the subject core literacy can effectively guide the teaching design of primary school science. The "time-measurement" large-unit teaching design resources and specific operation paths provide more specific guidance and case explanations for the large-unit teaching design aimed at cultivating students' science core literacy. (2) Under the guidance of this framework, the design and implementation of the "Measuring Time" large-unit teaching approach has significantly enhanced the development level of students' scientific core literacy, exhibiting advantages over traditional unit-based teaching methods.