[0002] The invention relates to devices, which provides a teaching method for geometric concepts relating to the circumference of a circle and for determining the value of the constant Tr (3.14). Across the nation, schools are going through a major reform in their math and science curriculum to bring education standards up to par. The facts show that there is an achievement gap between blacks and whites in mathematics and science. In 1999, when the latest National Assessment of Education Progress (NAEP) test was administered, large differences remained between average scores for blacks and Hispanics on the one hand, versus whites and Asians on the other. Nationally, the achievement gap did not narrow at all during the 1990s. In reading and math, gaps separating poor and minority students from others actually widened at most grade levels and remained the same or dropped only slightly at others (The Education Trust).

By the end of grade 4, African American, Latino and poor students of all races are already about two years behind other students. By the time they reach grade 8, they are about three years behind. By the time they reach grade 12, if they do so at all, minority students are about four years behind other young people. The mathematics and science skills of 1 7-year-old African American and Latino students are similar to those of 13- year-old white students. African Americans and Latinos obtain college degrees at only half the rate of white students. The partnerships between government agency, industry, academia and private organizations are trying to address these issues along with many others. This invention provides a method for teaching the geometric concepts of a circle.

[0003] 2) Prior Art The prior art consists of teaching the theory and equations for the geometry of a circle. Lessons primarily consist of a mathematical explanation for the circumference of a circle showing that C = Tr D or C = 2Trr. Demonstrations might include using a string or wire and placing it around the circumference of a circle. And then measure the length of the diameter and multiply it by 3.14 showing that it is about the same length as the string or wire. The present invention, as distinguished from the prior art, provides a device that clearly demonstrates that 3.14 diameter of a circle will fit around the circumference of that circle and that 6. 28 radius of a circle will fit around the circumference of that circle. None of the prior art uses a device or tool that provides a circular ring, along with diameter bars or radius bars that will fit around the circumference showing the relationship of rr and the diameter, or rr and the radius to the circumference of the circle.

Summary of Invention [0004] The present invention is designed to teach the relationship between a circle, its diameter and its radius.

[00051 One of the objectives of the present inventions is to provide a device that will bring the level of learning and understanding of the circumference of a circle to a conceptual level rather than just a fact remembering level as described in the Blooms Taxonomy.

[00061 Another objective is to clearly show that it takes 3.14 diameters to fit around the circumference of a circle by directly placing 3.14 diameters around the circumference.

[0007] Another objective is to clearly show that it takes 6.28 radius to fit around the circumference of a circle by directly placing 6.28 radius around the circumference.

[0008] Another objective is to clearly show that it takes 3.14 radius to fit half way around the circumference of a circle by directly placing 3.14 radius around half of the circumference.

[0009] Another objective is to show why rr is approximately equal to 3.14.

[0010] Another objective is to clearly show that when unit diameters are placed around the circumference, the resulting angles between each diameter will be at approximately 0, 114. 6,229. 2 and 343.8 degrees.

[00111 Another objective is to clearly show that when unit radius are placed around the circumference, the resulting angles between each radius will be at approximately 0, 57. 3, 114. 6, 171. 9, 229. 2, 286.5, and 343.8 degrees.

Brief Description of Drawings 10012] Fig. 1 is a plan view of the invention, including a circular ring designated by reference number 1, a rigid intersection bar representing its diameter designated by reference number 2, three full-length diameter bar designated by reference number 3, and a. 14 length diameter bar designated by reference number 4.

[0013] Fig. 2 is a top view of the invention showing where the three full-length diameter bars designated by reference number 3, and the. 14 length diameter bar designated by reference number 4 are attached around the circumference of the circle.

The diameter bars are spaced between angles of 0, 114. 6,229. 2,343. 8 and 360 degrees.

[0014] Fig. 3 is a plan view of the invention including a circular ring designated by reference number 5, a rigid intersection bar representing its radius designated by reference number 6, with six full-length radius bar designated by reference number 7, a . 28 length radius bar designated by reference number 9, and a. 14 length radius bar designated by reference number 8.

[0015] Fig. 4 is a top view of the invention showing where the six full-length radius bars designated by reference number 7, and the. 28 length radius bar designated by reference number 9 are attached around the circumference of the circle. The radius bars are spaced between angles of 0,57. 3, 114. 6, 171.9, 229. 2, 286.5, 343.8 and 360 degrees.

Detailed Description [0016] The present invention relates to a device designed to teach the relationship between a circle, its diameter and its radius.

L0017] Referring to Fig 1, the device includes a circular ring designated by reference number 1, that has a rigid intersecting bar representing its diameter designated by reference number 2. The intersecting bar has marked off units dividing the bar into segments. The ring also has marked off units around the 360 degrees of the circle.

Flexible bars the same size as the diameter designated by reference number 3 are available to attach around the outer perimeter by way of an attachment mechanism. An additional flexible bar is available at. 14 diameters in length designated by reference number 4. When the flexible diameter bars are attached to the circular ring, three diameters bars and one. 14 diameter bar are affixed to the ring representing 3.14 diameters.

[0018] Referring to Fig 3, the circular ring designated by reference number 5, now has a rigid intersecting bar representing its diameter and showing the radius of the circle designated by reference number 6,. The intersecting bar has marked off units dividing the radius into segments. Flexible bars the same size as the radius designated by reference number 7, are available to attach to the outer perimeter by way of an attachment mechanism. An additional flexible bar is available at. 28 radiuses in length designated by reference number 9. When the flexible radius bars are attached to the circular ring, six radius bars and one. 28 radius bar are affixed to the ring representing 6.28 radius.

100191 Another additional flexible bar is available at. 14 radiuses in length designated by reference number 8. When the flexible radius bars are attached to half of the circular ring, three radius bars and one. 14 radius bar are affixed to the ring representing 3.14 radius.

10020] Classroom activities can be developed using the present invention that will increase the level of understanding of the circumference of a circle and the value of TT (3.14). By attaching three diameter bars and one. 14 diameter bar around the circumference of the ring, students can immediately see and understand the equation, circumference = 3. 14 diameters (C = rrD). And it becomes clear why Tr = 3.14.

[0021] By attaching six radius bars and one. 28 radius bar around the circumference of the ring, students can immediately see and understand the equation, circumference = 6.28 radius. Or written another way, circumference = 2 x 3.14 radius (C = 2 rrr).

[0022] By attaching three radius bars and one. 14 radius bar around half of the ring, students can immediately see and understand that half of the circumference = 3. 14 radius (1/2 x C = Trr).

[0023] Participating in these activities brings the level of learning and understanding of the circumference of a circle to a conceptual level rather than just a fact remembering level as described in the Blooms Taxonomy.