How to make a Clock on Geometer's Sketchpad

In this video there is an explanation about how to construct a clock that the minute hand and hour hand depends on second hand's motion. It is good for students to see the relation between hour, minute and second and also it allows to see the how the angle is changing between them.

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Objectives:

5^th Grade:

·         Zaman ölçü birimlerini tanır, birbirine dönüştürür ve ilgili problemleri çözer.

6^th Grade:

·         Aynı veya farklı birimlerdeki iki çokluğun birbirine oranını belirler.

7^th Grade:

·         Çemberde merkez açıları, gördüğü yayları ve ölçüleri arasındaki ilişkileri belirler.

Pedagogical Explanation:

For 5^th grade, the main point is to discover how to interpret an analog clock and how the relations among time measurement units. Although there is a reasoning behind why 1 hour equals to 60minutes or why 1 minute equals to 60 seconds, students tend to memorize these equalities rather than querying the concept in detail and internalizing it. In order to create an awareness of what the main idea behind, the objective (Zaman ölçü birimlerini tanır, birbirine dönüştürür ve ilgili problemleri çözer.) is choosen to clarify with the guidance of this new clock tool. Thanks to this tool, they will be able to recognize a second hand returns 60 tours while a minute hand turns just one tour and vice versa. Moreover, students will be able to have a sense of the concepts ratio and angle before they learned about them.

For 6^th grade, what makes the clock tool efficient is its demonstrating power. The subject of ratio is a confusing thing not just for primary school students, even for elementary school students most of the time. The fundamental reason behind this is to learn the concept without any visual interactions and more concrete & real examples. Here, what the clock tool enables students is to observe a real situation and realize the ratio of different units inside of the concept. So that, they can increase their awareness of ratio concept in a concrete way. Further, this tool provides students with an observation of second hand and minute hand separately in distinct clocks; therefore, it is easier to comprehend the relation and ratio between them.

For 7^th grade, angle concept is a cornerstone for geometry. Even though students understand basics of that subject, they have several troubles on creating relations between the concepts, angle and circle. Correspondingly, the clock tool responds this need and benefits to the objection (Çemberde merkez açıları, gördüğü yayları ve ölçüleri arasındaki ilişkileri belirler.). Clock is one of the most related tools for realizing the relation between central angle and its arc. Since hours symbolize arc and hands represent central angle, clarifying their relation will be clearer.