measurement tools. Notice how Carolina emphasizes the distance between hash marks on the ruler as 1 centimeter and then verifies with a centimeter cube before leading students in guided practice: Carolina: “Watch as I label the distance between the hash marks. One endpoint of a ruler is called the zero point. That’s because we start measuring from zero to the first hash mark, which is 1 centimeter. The distance between two hash marks is 1 centimeter. I can verify the distance by lining up my centimeter cube.” Carolina demonstrates how a centimeter cube perfectly fits between the zero point and the first hash mark. Carolina: “I am going to start at the endpoint and label the first hash mark with the numeral 1. This 1 means that the distance from the endpoint to the first hash mark is 1 centimeter.” Carolina models labeling the next hash mark with the numeral 2 and the next with the numeral 3. Then she leads students to verify the distance between hash marks using their own centimeter cubes and to label the first three hash marks. Throughout guided practice, Carolina monitors student work and provides feedback to ensure that students are developing the conceptual understanding that the distance between any two hash marks is 1

中文翻译：

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建立对线性测量的概念理解：教有数学学习障碍的学生

测量工具。请注意卡罗莱纳如何强调标尺上哈希标记之间的距离为 1 厘米，然后在引导学生进行指导练习之前用厘米立方体进行验证：卡罗莱纳：“看着我标记哈希标记之间的距离。标尺的一个端点称为零点。那是因为我们从零开始测量到第一个哈希标记，即 1 厘米。两个哈希标记之间的距离为 1 厘米。我可以通过排列我的厘米立方体来验证距离。” Carolina 演示了厘米立方体如何完美地放置在零点和第一个哈希标记之间。Carolina：“我将从端点开始，用数字 1 标记第一个哈希标记。这个 1 表示从端点到第一个哈希标记的距离是 1 厘米。”Carolina 模型用数字 2 标记下一个哈希标记，然后用数字 3 标记下一个。然后她带领学生用自己的厘米立方体验证哈希标记之间的距离，并标记前三个哈希标记。在整个指导练习中，Carolina 会监控学生的工作并提供反馈，以确保学生对任意两个哈希标记之间的距离为 1 形成概念性理解