Combined multifunctional mathematics teaching instrument

Abstract

The invention discloses a combined multifunctional mathematics teaching instrument, and relates to the technical field of mathematics teaching, the combined multifunctional mathematics teaching instrument comprises a semicircular protractor, the protractor is provided with angle scale marks, the central point of the protractor is movably connected with a ruler through an I-shaped rotating shaft, the ruler is provided with length scale marks, and the central lines of the protractor and the I-shaped rotating shaft coincide. The part of the I-shaped rotating shaft at the bottom of the protractor is embedded in the protractor. The part, located at the bottom of the protractor, of the I-shaped rotating shaft is embedded into the protractor, the lower surface of the I-shaped rotating shaft and the lower surface of the protractor are coplanar, when an arc line needs to be drawn, the protractor can be attached to a blackboard and can be fixed in a hand pressing mode, or the I-shaped rotating shaft is made of a magnetic attraction material and can be attracted to the blackboard, and therefore the arc line can be drawn conveniently. Subsequent operation is facilitated, and the problem that the accuracy of arc line drawing, straight line drawing and other operations is affected due to the fact that the left portion of the protractor and the rotating plate cannot be attached to the plane is solved.

Description

Technical Field

[0001] This invention relates to the field of mathematics teaching technology, specifically to a combined multifunctional mathematics teaching instrument. Background Technology

[0002] Geometry in mathematics is the study of geometric figures. In geometry teaching, teachers often need to draw geometric figures by hand on the blackboard to help students intuitively understand geometric structures. Commonly used drawing teaching aids include rulers, set squares, compasses, protractors, etc.

[0003] A search revealed Chinese Patent Publication No. CN108773235A, which discloses a combined mathematical teaching drawing instrument, comprising a right protractor, a left protractor, a chalk clamp, a rotating plate, a reflector, and a fastening sleeve. The left protractor is mounted on the left side of the right protractor, and the right and left protractors are rotatably connected via a rotating shaft. The right protractor has length scale lines, and the upper end of the right protractor has a chalk clamp fitted with a fastening sleeve. The upper part of the chalk clamp has a chalk placement groove. The rotating plate is mounted on the right protractor, and angle scale lines are provided on the outer arc edge of the rotating plate. The rotating plate has triangular and pentagonal holes, and a reflector is mounted on the rotating plate. A first magnetic block is mounted on the straight edge of one side of the rotating plate, and a second magnetic block is mounted on the left protractor. This invention has advantages such as ease of use and solves the problem of inconvenience in use.

[0004] The aforementioned instrument still suffers from the following problems in practical use: There is a height difference between the rotating shaft and the left side of the protractor and the rotating plate, preventing the left side of the protractor and the rotating plate from being flush with the plane during use. This affects the accuracy of drawing arcs and straight lines. Furthermore, the position of the clamp used to hold the chalk cannot be adjusted between the right side of the protractor, resulting in a fixed diameter for the drawn arcs and failing to meet the needs of diverse drawing styles in actual operation. Therefore, this application proposes a combined multifunctional mathematical teaching instrument to solve the above problems. Summary of the Invention

[0005] This invention provides a combined multifunctional mathematics teaching instrument to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A combined multifunctional mathematical teaching instrument includes a protractor, which is semi-circular and has angle scale lines. The center point of the protractor is movably connected to a ruler via an I-shaped rotating shaft. The ruler has length scale lines. The center lines of the protractor and the I-shaped rotating shaft coincide. The part of the I-shaped rotating shaft at the bottom of the protractor is embedded in the protractor, and the lower surface of the I-shaped rotating shaft is coplanar with the lower surface of the protractor.

[0008] The ruler has a sliding groove in the middle, and a piece of chalk is movably connected in the sliding groove. The zero mark on the ruler corresponds to the center line of the protractor and the I-shaped rotating shaft. When the chalk moves along the sliding groove to different positions, it represents the radius of different circles.

[0009] The ruler has a rotating groove at the contact point with the protractor. The height of the rotating groove is the same as the thickness of the protractor. The lower surface of the ruler is coplanar with the lower surface of the protractor.

[0010] When the protractor is fixed to the blackboard, the ruler can rotate along the I-shaped axis. Draw a circle with the intersection of the center line of the protractor, the center line of the I-shaped axis, and the blackboard as the center and the distance of the chalk from the center line of the protractor and the I-shaped axis as the radius.

[0011] A further improvement of the technical solution of the present invention is that: a transparent indicator plate is fixedly connected at the overlap between the inner wall of the sliding groove and the rotating groove. The transparent indicator plate is made of transparent material and has an indicator line. One end of the indicator line is extended and intersects the center line of the protractor and the I-shaped rotating shaft. The horizontal line drawn by the chalk along the sliding groove is collinear with the indicator line.

[0012] A further improvement of the technical solution of the present invention is that: a limiting groove is provided on both sides of the sliding groove, a limiting slider is movably connected to the inner wall of the limiting groove, an installation sleeve is fixedly connected to one side of the limiting slider, a through groove is provided at the bottom of the installation sleeve, the bottom of the installation sleeve is higher than the lower surface of the ruler, the chalk is movably connected to the inside of the installation sleeve, and one end of the chalk extending to the outside of the through groove is flush with the lower surface of the ruler.

[0013] A further improvement of the technical solution of the present invention is that: a sleeve is movably connected to the top of the chalk, an inner plate is threadedly connected to the outer surface of the sleeve, an adjustment groove is provided on the inner plate, a vertical adjustment rod is movably connected to the inner wall of the adjustment groove, and one end of the vertical adjustment rod is fixedly connected to the bottom of the inner cavity of the mounting sleeve.

[0014] A further improvement of the technical solution of the present invention is that a limiting plate is fixedly connected to the top end of the vertical adjusting rod.

[0015] A further improvement of the technical solution of the present invention is that: a spring is sleeved on the outer surface of the vertical adjustment rod inside the mounting sleeve. When the chalk is not worn out and its length is at its maximum, the spring is in a stretched state. When the chalk is worn out due to continuous drawing, causing the length of the chalk to shorten, the spring gradually retracts, so that the bottom of the chalk is always in contact with the blackboard.

[0016] A further improvement of the technical solution of the present invention is that: the inner plate is movably connected to the side of the outer plate, the inner side of the outer plate is provided with a rotating groove, the side of the inner plate is fixedly connected to a rotating limiting ring, the outer surface of the rotating limiting ring is movably connected to the inner wall of the rotating groove, the two sides of the rotating limiting ring are fixedly connected to locking blocks, the mounting sleeve is provided with a vertical sliding groove and a locking groove, when the locking block is rotated to engage with the vertical sliding groove, the locking block can slide along the vertical sliding groove to the bottom of the inner cavity of the mounting sleeve, when the locking block is rotated to engage with the locking groove, the chalk cannot slide down along the vertical adjusting rod.

[0017] A further improvement of the technical solution of the present invention is that a lifting handle is fixedly connected to the upper surface of the outer plate.

[0018] A further improvement of the technical solution of the present invention is that: both sides of the mounting sleeve are fixedly connected with indicator arrows.

[0019] A further improvement of the technical solution of the present invention is that a fixing bolt is threaded onto the indicator arrow.

[0020] Due to the adoption of the above technical solution, the technical progress achieved by this invention compared to the prior art is as follows:

[0021] 1. This invention provides a combined multifunctional mathematical teaching instrument. The part of the I-shaped rotating shaft located at the bottom of the protractor is embedded in the protractor. The lower surface of the I-shaped rotating shaft is coplanar with the lower surface of the protractor. When it is necessary to draw an arc, the protractor can be attached to the blackboard and fixed by hand, or the I-shaped rotating shaft can be made of magnetic material and can be adsorbed onto the blackboard for easy subsequent operation. This avoids the problem that the left side of the protractor and the rotating plate cannot be attached to the plane, which affects the accuracy of drawing arcs, straight lines and other operations.

[0022] 2. This invention provides a combined multifunctional mathematical teaching instrument. When the protractor is fixed on the blackboard, the ruler can rotate along the I-shaped axis. The intersection of the center line of the protractor and the I-shaped axis with the blackboard is used as the center, and the distance between the chalk and the center line of the protractor and the I-shaped axis is used as the radius to draw a circle or an arc. The radius can be adjusted according to actual needs to meet the needs of various drawing styles in actual operation.

[0023] 3. This invention provides a combined multifunctional mathematical teaching instrument. When chalk is needed for drawing lines, the outer plate, inner plate, clip, and chalk are moved upward by pulling the handle upward. Then, the outer plate is rotated so that the locking block aligns with the vertical slide groove. At this time, under the action of the tension spring, the chalk moves downward to abut against the blackboard. As the line is drawn, the chalk wears down and becomes shorter, and the tension spring shortens continuously, so that the chalk is always in contact with the blackboard during the working process. When drawing lines is not needed, the handle is lifted and rotated so that the locking block engages with the locking slot. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention;

[0025] Figure 2 This is a schematic cross-sectional view of the connection between the protractor, ruler, and I-shaped pivot of the present invention.

[0026] Figure 3 This is a schematic diagram of the protractor of the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of the ruler of the present invention with a rotating groove at the bottom;

[0028] Figure 5 This is a schematic diagram of the structure when the indicator line on the ruler of the present invention is aligned with the zero mark line of the protractor;

[0029] Figure 6 For the present invention Figure 1 Enlarged structural diagram at point A;

[0030] Figure 7 This is a cross-sectional structural diagram of the mounting sleeve after the locking block and the locking slot of the present invention are engaged;

[0031] Figure 8 This is a schematic cross-sectional view of the mounting sleeve after the locking block and the vertical slide groove of the present invention are connected.

[0032] Figure 9 This is a schematic diagram of the structure of the mounting sleeve of the present invention;

[0033] Figure 10 This is a schematic diagram of the structure of the I-shaped rotating shaft of the present invention;

[0034] Figure 11 This is a schematic diagram of the outer panel of the present invention;

[0035] Figure 12 This is a schematic diagram of the inner plate structure of the present invention;

[0036] Figure 13 This is a schematic cross-sectional view of the connection between the outer and inner panels of the present invention.

[0037] In the diagram: 1. Protractor; 2. Ruler; 3. I-shaped pivot; 4. Transparent indicator plate; 5. Rotating groove; 6. Sliding groove; 7. Limiting groove; 8. Limiting slider; 9. Mounting sleeve; 10. Chalk; 11. Clip; 12. Cross plate; 13. Inner plate; 14. Adjusting groove; 15. Vertical adjusting rod; 16. Spring; 17. Limiting plate; 18. Outer plate; 19. Lifting handle; 20. Rotating limiting ring; 21. Rotating slot; 22. Locking block; 23. Vertical sliding groove; 24. Locking slot; 25. Through groove; 26. Indicator arrow; 27. Fixing bolt. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to embodiments:

[0039] Example:

[0040] like Figure 1-13 As shown, this invention provides a combined multifunctional mathematical teaching instrument, including a protractor 1, which is semi-circular and has angle scale lines from 0 to 180 degrees. A ruler 2 is movably connected to the center point of the protractor 1 via an I-shaped rotating shaft 3. The I-shaped rotating shaft 3 is fixedly connected to the protractor 1. The protractor 1 and the I-shaped rotating shaft 3 are fixed, and the ruler 2 can rotate around the I-shaped rotating shaft 3 to draw circles or arcs. The ruler 2 has length scale lines and can be used to draw straight lines or measure the length of straight lines. The center lines of the I-shaped rotating shaft 3 coincide, and the part of the I-shaped rotating shaft 3 located at the bottom of the protractor 1 is embedded in the protractor 1. The lower surface of the I-shaped rotating shaft 3 is coplanar with the lower surface of the protractor 1. When it is necessary to draw an arc, the protractor 1 can be attached to the blackboard. It can be fixed by pressing it with your hand, or the I-shaped rotating shaft 3 can be made of magnetic material and can be attached to the blackboard to facilitate subsequent operations. This avoids the problem that the left side of the protractor and the rotating plate cannot be attached to the plane, which affects the accuracy of drawing arcs, straight lines and other operations.

[0041] A sliding groove 6 is provided in the middle of the ruler 2, and a piece of chalk 10 is movably connected in the sliding groove 6. The zero mark on the ruler 2 corresponds to the center line of the protractor 1 and the I-shaped rotating shaft 3. When the chalk 10 moves along the sliding groove 6 to different positions, it represents the radius of different circles.

[0042] A rotating groove 5 is provided at the contact part between the ruler 2 and the protractor 1. The height of the rotating groove 5 is the same as the thickness of the protractor 1. The lower surface of the ruler 2 is coplanar with the lower surface of the protractor 1, so that when the ruler 2 rotates along the I-shaped rotating shaft 3, the rotating groove 5 slides against the outer surface of the protractor 1 without being affected.

[0043] When the protractor 1 is fixed on the blackboard, the ruler 2 can rotate along the I-shaped axis 3. With the intersection of the center line of the protractor 1, the I-shaped axis 3 and the blackboard as the center, a circle or arc can be drawn with the distance of the chalk 10 from the center line of the protractor 1 and the I-shaped axis 3 as the radius. This radius can be adjusted according to actual needs to meet the needs of various drawing styles in actual operation.

[0044] Furthermore, a transparent indicator plate 4 is fixedly connected to the inner wall of the sliding groove 6 at the overlap with the rotating groove 5. The transparent indicator plate 4 is made of transparent material and has an indicator line. One end of the indicator line is extended and intersects the center line of the protractor 1 and the I-shaped rotating shaft 3. The chalk 10 is collinear with the horizontal line drawn along the sliding groove 6 and the indicator line.

[0045] When you need to draw a triangle with a fixed length and the included angle of two sides, first, draw a straight line of a fixed length using chalk 10 at any position, such that the length of one side of the triangle is equal to the radius of the line plus the radius of the protractor 1. Then, using the angle scale line on the protractor 1 as the initial point, rotate the ruler 2 by a certain angle so that the angle corresponds to the angle of one side of the triangle you are drawing. Next, draw the length of the other side of the triangle corresponding to that angle using chalk 10. Then, extend the two drawn sides to intersect, and connect the other ends of the two drawn sides to obtain a triangle with a fixed length and the included angle of two sides.

[0046] Furthermore, limiting grooves 7 are provided on both sides of the sliding groove 6. Limiting sliders 8 are movably connected to the inner wall of the limiting grooves 7. A mounting sleeve 9 is fixedly connected to one side of the limiting slider 8. A through groove 25 is provided at the bottom of the mounting sleeve 9. The bottom of the mounting sleeve 9 is higher than the lower surface of the ruler 2. The chalk 10 is movably connected to the inside of the mounting sleeve 9. One end of the chalk 10 extending to the outside of the through groove 25 is flush with the lower surface of the ruler 2. By sliding the mounting sleeve 9, the chalk 10 can slide along the limiting groove 7 to different positions to correspond to different radius requirements of the circle.

[0047] Furthermore, a sleeve 11 is movably connected to the top of the chalk 10. The chalk 10 and the sleeve 11 can be connected in various detachable and convenient ways, such as using an elastic rubber sleeve on the inner side of the sleeve 11 for easy replacement when the chalk 10 is worn out. An inner plate 13 is threadedly connected to the outer surface of the sleeve 11. An adjustment groove 14 is provided on the inner plate 13, and a vertical adjustment rod 15 is movably connected to the inner wall of the adjustment groove 14. One end of the vertical adjustment rod 15 is connected to the bottom of the inner cavity of the mounting sleeve 9. The sleeve 11 is fixedly connected to the top of the cross plate 12. When the chalk 10 is used up and needs to be replaced, the sleeve 11 can be rotated by the cross plate 12 to separate the sleeve 11 from the inner plate 13. After the sleeve 11 is taken out and replaced with a new chalk 10, the sleeve 11 can be reconnected to the inner plate 13. When the chalk 10 is worn out during use, the inner plate 13 will gradually move down along the vertical adjustment rod 15 to ensure that the bottom of the chalk 10 always touches the blackboard.

[0048] Furthermore, a limit plate 17 is fixedly connected to the top of the vertical adjustment rod 15 to limit the sliding range of the inner plate 13.

[0049] Furthermore, a spring 16 is fitted on the outer surface of the vertical adjustment rod 15 inside the mounting sleeve 9. When the chalk 10 is not worn out and its length is at its maximum, the spring 16 is in a stretched state. When the chalk 10 is worn out due to continuous drawing, causing the length of the chalk 10 to shorten, the spring 16 gradually retracts, so that the bottom of the chalk 10 is always in contact with the blackboard.

[0050] Furthermore, an outer plate 18 is movably connected to the side of the inner plate 13. A rotating groove 21 is provided on the inner side of the outer plate 18. A rotating limiting ring 20 is fixedly connected to the side of the inner plate 13. The outer surface of the rotating limiting ring 20 is movably connected to the inner wall of the rotating groove 21. Locking blocks 22 are fixedly connected to both sides of the rotating limiting ring 20. A vertical sliding groove 23 and a locking groove 24 are correspondingly provided on the mounting sleeve 9. When the locking block 22 is rotated to engage with the vertical sliding groove 23, the locking block 22 can slide along the vertical sliding groove 23 to the bottom of the inner cavity of the mounting sleeve 9. When the locking block 22 is rotated to engage with the locking groove 24, the chalk 10 cannot slide down along the vertical adjusting rod 15.

[0051] When chalk 10 is not needed for drawing lines, locking block 22 engages with locking slot 24, preventing chalk 10 from moving downwards. When chalk 10 is needed for drawing lines, outer plate 18 is moved upwards, causing outer plate 18 and inner plate 13 to move along vertical adjustment rod 15 to the outside of mounting sleeve 9. Then, outer plate 18 is rotated, causing locking block 22 to abut against vertical slide groove 23. At this time, chalk 10, under the action of tension spring 16, generates a downward force, causing chalk 10 to abut against the blackboard. When chalk 10 wears out or shortens, inner plate 13 moves downwards along vertical adjustment rod 15, ensuring that chalk 10 remains in contact with the blackboard.

[0052] Furthermore, a lifting handle 19 is fixedly connected to the upper surface of the outer plate 18. Since the spring 16 is initially in a stretched state, when the chalk 10 is needed to draw lines, the lifting handle 19 must first be pulled upwards to move the outer plate 18, inner plate 13, clip 11, and chalk 10 upwards together. Then, the outer plate 18 is rotated so that the locking block 22 is aligned with the vertical slide groove 23. At this time, under the action of the tension spring 16, the chalk 10 moves downwards to abut against the blackboard. As the lines are drawn, the chalk 10 is continuously worn down and shortened, and the tension spring 16 is continuously shortened, so that the chalk 10 is always in contact with the blackboard during the working process. When lines are not needed, the lifting handle 19 is lifted and rotated so that the locking block 22 is engaged with the locking slot 24.

[0053] Furthermore, indicator arrows 26 are fixedly connected to both sides of the mounting sleeve 9, and length scale lines are set on both sides of the ruler 2 located in the sliding groove 6 for easy observation. When the chalk 10 slides along the sliding groove 6, the indicator arrows 26 correspond to the length scale lines, making it easy to accurately measure the length of the line drawn by the chalk 10. Due to the presence of the protractor 1, the actual length of the line drawn by the chalk 10 is the length indicated by the indicator arrows 26 minus the radius of the protractor 1.

[0054] Furthermore, a fixing bolt 27 is threaded onto the indicator arrow 26. The outer surface of the fixing bolt 27 has a groove to increase friction and facilitate rotation of the fixing bolt 27. When a circle needs to be drawn with a fixed radius, the mounting sleeve 9 is slid along the sliding groove 6 and the limiting groove 7. Through the indication of the indicator arrow 26, the distance between the corresponding position of the chalk 10 and the center line of the protractor 1, the ruler 2, and the I-shaped rotating shaft 3 is the radius of the circle to be drawn. At this time, by rotating the fixing bolt 27, the bottom of the fixing bolt 27 abuts against the upper surface of the ruler 2, generating a downward force, so that the positions of the mounting sleeve 9 and the chalk 10 are relatively fixed. When the ruler 2 rotates around the I-shaped rotating shaft 3 to draw a circle, the chalk 10 will not shift its position, ensuring the stability and accuracy of the circle drawing process.

Claims

1. A combined multifunctional mathematical teaching instrument, characterized in that: Includes a protractor (1), which is semi-circular and has angle scale lines. The center point of the protractor (1) is movably connected to a ruler (2) through an I-shaped rotating shaft (3). The ruler (2) has length scale lines. The center lines of the protractor (1) and the I-shaped rotating shaft (3) coincide. The part of the I-shaped rotating shaft (3) at the bottom of the protractor (1) is embedded in the protractor (1). The lower surface of the I-shaped rotating shaft (3) is coplanar with the lower surface of the protractor (1). The ruler (2) has a sliding groove (6) in the middle, and a piece of chalk (10) is movably connected in the sliding groove (6). The zero mark on the ruler (2) corresponds to the center line of the protractor (1) and the I-shaped rotating shaft (3). When the chalk (10) moves along the sliding groove (6) to different positions, it represents the radius of different circles. The ruler (2) has a rotating groove (5) at the contact part with the protractor (1). The height of the rotating groove (5) is the same as the thickness of the protractor (1). The lower surface of the ruler (2) is coplanar with the lower surface of the protractor (1). When the protractor (1) is fixed on the blackboard, the ruler (2) can rotate along the I-shaped axis (3). The intersection of the center line of the protractor (1), the I-shaped axis (3) and the blackboard is used as the center, and the distance of the chalk (10) from the center line of the protractor (1) and the I-shaped axis (3) is used as the radius to draw a circle.

2. The combined multifunctional mathematical teaching instrument according to claim 1, characterized in that: A transparent indicator plate (4) is fixedly connected to the inner wall of the sliding groove (6) and the overlapping part of the rotating groove (5). The transparent indicator plate (4) is made of transparent material and has an indicator line. One end of the indicator line is extended and intersects the center line of the protractor (1) and the I-shaped rotating shaft (3). The horizontal line drawn by the chalk (10) along the sliding groove (6) is collinear with the indicator line.

3. The combined multifunctional mathematical teaching instrument according to claim 1, characterized in that: The sliding groove (6) has limit grooves (7) on both sides. Limit sliders (8) are movably connected to the inner wall of the limit grooves (7). A mounting sleeve (9) is fixedly connected to one side of the limit sliders (8). A through groove (25) is provided at the bottom of the mounting sleeve (9). The bottom of the mounting sleeve (9) is higher than the lower surface of the ruler (2). The chalk (10) is movably connected to the inside of the mounting sleeve (9). One end of the chalk (10) extending to the outside of the through groove (25) is flush with the lower surface of the ruler (2).

4. The combined multifunctional mathematical teaching instrument according to claim 3, characterized in that: The top of the chalk (10) is movably connected to a sleeve (11), and the outer surface of the sleeve (11) is threadedly connected to an inner plate (13). An adjustment groove (14) is provided on the inner plate (13), and a vertical adjustment rod (15) is movably connected to the inner wall of the adjustment groove (14). One end of the vertical adjustment rod (15) is fixedly connected to the bottom of the inner cavity of the mounting sleeve (9).

5. A combined multifunctional mathematical teaching instrument according to claim 4, characterized in that: The top end of the vertical adjusting rod (15) is fixedly connected to a limiting plate (17).

6. A combined multifunctional mathematical teaching instrument according to claim 4, characterized in that: The vertical adjustment rod (15) is fitted with a spring (16) on the outer surface inside the mounting sleeve (9). When the chalk (10) is not worn out and its length is at its maximum, the spring (16) is in a stretched state. When the chalk (10) is worn out due to continuous drawing, causing the length of the chalk (10) to shorten, the spring (16) gradually retracts, so that the bottom of the chalk (10) is always in contact with the blackboard.

7. A combined multifunctional mathematical teaching instrument according to claim 4, characterized in that: The inner plate (13) is movably connected to the outer plate (18) on its side. The outer plate (18) has a rotating slot (21) on its inner side. The inner plate (13) is fixedly connected to a rotating limiting ring (20). The outer surface of the rotating limiting ring (20) is movably connected to the inner wall of the rotating slot (21). Locking blocks (22) are fixedly connected to both sides of the rotating limiting ring (20). The mounting sleeve (9) has a vertical sliding groove (23) and a locking slot (24) respectively. When the locking block (22) is rotated to engage with the vertical sliding groove (23), the locking block (22) can slide along the vertical sliding groove (23) to the bottom of the inner cavity of the mounting sleeve (9). When the locking block (22) is rotated to engage with the locking slot (24), the chalk (10) cannot slide down along the vertical adjusting rod (15).

8. A combined multifunctional mathematical teaching instrument according to claim 7, characterized in that: A lifting handle (19) is fixedly connected to the upper surface of the outer panel (18).

9. A combined multifunctional mathematical teaching instrument according to claim 3, characterized in that: Indicator arrows (26) are fixedly connected to both sides of the mounting sleeve (9).

10. A combined multifunctional mathematical teaching instrument according to claim 9, characterized in that: The indicator arrow (26) is threaded with a fixing bolt (27).

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