CN208842088U - A kind of dedicated practice blackboard of primary school mathematics calculating - Google Patents

Abstract

The utility model relates to a kind of blackboards more particularly to a kind of primary school mathematics to calculate dedicated practice blackboard.The purpose of the utility model is to provide a kind of write area greatly and can the primary school mathematics of quick erasing chalk word calculate dedicated practice blackboard.Technical solution: a kind of dedicated practice blackboard of primary school mathematics calculating includes left support, right support, the first cabinet, the second cabinet, left electronic reel, right electronic reel, drawstring etc.；Upper end is equipped with the first cabinet between left support and right support, and lower end is equipped with the second cabinet between left support and right support, and bottom left is symmetrically arranged with left electronic reel in the first cabinet inner top left side and the second cabinet.The utility model passes through the left electronic reel of setting and right electronic reel, teacher opens left electronic reel and right electronic reel, left electronic reel and right electronic reel, which pass through drawstring, to drive calculating to be moved left and right with blackboard, facilitate classmate while appearing on the stage and practice, enhance practicability.

Description

A kind of dedicated practice blackboard of primary school mathematics calculating

Technical field

The utility model relates to a kind of blackboards more particularly to a kind of primary school mathematics to calculate dedicated practice blackboard.

Background technique

On mathematical education classroom, in order to understand the study situation of student in time, teacher can write on blackboard Answer on topic, then some students to blackboard that call the roll is referred to for students since teacher can also write some notes on blackboard, is led Cause teacher when setting a question, blackboard spatial position may be inadequate, but cannot wipe the notes on blackboard, so teacher can only Set a question according to the range that can be write on blackboard；After teacher has explained the answer of student's writing, require to wipe answer, due to The area of blackboard eraser is smaller, and teacher needs to expend the regular hour when wiping answer, therefore can waste time to cause to influence to attend class Process.

Utility model content

In order to overcome teacher when setting a question, blackboard spatial position may not enough and blackboard eraser erases the board needs consuming centainly Time the shortcomings that, the purpose of the utility model is to provide a kind of write area greatly and can quick erasing chalk word primary school mathematics Calculate dedicated practice blackboard.

Technical solution: a kind of primary school mathematics calculate dedicated practice blackboard, include left support, right support, the first cabinet, the Two cabinets, left electronic reel, right electronic reel, drawstring, the first sliding rail, the first sliding block, the second sliding block, connecting rod, calculating With blackboard, the second sliding rail, third sliding block, the first spring, blackboard eraser and handle, upper end is equipped with first between left support and right support Cabinet, lower end is equipped with the second cabinet between left support and right support, and bottom is left in the first cabinet inner top left side and the second cabinet Side is symmetrically arranged with left electronic reel, on the right side of the first cabinet inner top and in the second cabinet bottom right be symmetrically arranged with it is right it is electronic around Drawstring, bottom in the first cabinet inner top and the second cabinet are symmetrically wound on line wheel, left electronic reel and right electronic reel Be symmetrically arranged with the first sliding rail, at the top of top the first sliding rail bottom and the first sliding rail of lower section symmetrical slidingtype be connected with the first sliding block and Second sliding block, the first sliding block are located at the second sliding block left, connect on the left of left drawstring end and the first sliding block, right drawstring end It is connect with the second sliding block right side, connecting rod is equipped between the first sliding block and the second sliding block, the first sliding block of both up and down and second are slided It is equipped with calculating blackboard between block, the second sliding rail is equipped at left and right sides of calculating blackboard, slidingtype connection on front side of the second sliding rail There is third sliding block, the first spring, two sides first of left and right are symmetrically connected on the left of left third sliding block right side and right third sliding block Spring end is equipped with blackboard eraser, and middle part is equipped with handle on front side of blackboard eraser.

Furthermore, it is therefore particularly preferred that further include having sleeve, second spring, pointed cone, collecting box, first baffle and third bullet Spring is calculated with sleeve is symmetrically and evenly equipped at left and right sides of blackboard lower part, and rear side is equipped with second spring, second spring front end in sleeve Equipped with pointed cone, calculating blackboard underside of forward bilateral symmetry is equipped with collecting box, and collecting box is located on the downside of sleeve, and collecting box front end turns Dynamic formula is connected with first baffle, and first baffle and collecting box cooperate, and middle part left and right ends are equipped with third bullet on rear side of first baffle Spring, third spring end are connect with collecting box bottom inside.

Furthermore, it is therefore particularly preferred that further include having placing box, second baffle and handle, right support lower right side is equipped with and puts Case is set, placing box bottom is provided with groove, and lower end is provided with through-hole on the right side of placing box, and through-hole and groove are in same level, through-hole It is inside placed with second baffle, second baffle left end is located in groove, and second baffle right side central is equipped with handle.

The utility model is mounted on front side of blackboard, and teacher inscribes mathematical computations on the left of calculating blackboard, when teacher needs When wanting classmate to appear on the stage to practice, teacher starts left electronic reel and right electronic reel work, and left electronic reel reels Rope, right electronic reel puts drawstring, and then the first sliding block and the second sliding block is driven to slide to the left on the first sliding rail, calculates with black Plate is moved to the left therewith, and when calculating is moved to the left predetermined position with blackboard, teacher closes left electronic reel and the right side is electronic Reel, the first sliding block, the second sliding block and the stopping of calculating blackboard are moved to the left, and it is right in calculating blackboard then to select classmate again Side and blackboard right positions are calculated, and after these classmates calculate, teacher restarts left electronic reel and the right side is electronic Reel work, left electronic reel put drawstring, and right electronic reel reels rope, and then the first sliding block and the second sliding block is driven to exist It is slided to the right on first sliding rail, calculating is moved right therewith with blackboard, when calculating is moved right with blackboard to predetermined position, always Teacher closes left electronic reel and right electronic reel, and the first sliding block, the second sliding block and the stopping of calculating blackboard move right, so It selects other classmates again afterwards to calculate in blackboard leftward position, more classmates can be allowed to appear on the stage in this way and practiced, to same Learn be also a kind of exercise, when needing to wipe blackboard, teacher holds the handle on blackboard eraser and wipes, to calculating blackboard Right blackboard eraser can be used to be wiped for right side and blackboard right part, and can make on the left of calculating blackboard with blackboard left part It is wiped with left blackboard eraser, when blackboard eraser wipes blackboard up and down, blackboard eraser drives the first spring to move up and down, and then band Dynamic third sliding block moves up and down on the second sliding rail, and when blackboard eraser is finished, blackboard eraser is put into calculating blackboard lower part by teacher, It will not influence classmate in this way to be practiced in calculating on blackboard.

Because further including having sleeve, second spring, pointed cone, collecting box, first baffle and third spring, under calculating blackboard Sleeve is symmetrically and evenly equipped at left and right sides of portion, rear side is equipped with second spring in sleeve, and second spring front end is equipped with pointed cone, calculates and uses Blackboard underside of forward bilateral symmetry is equipped with collecting box, and collecting box is located on the downside of sleeve, and collecting box front end rotary type is connected with first Baffle, first baffle and collecting box cooperate, and middle part left and right ends are equipped with third spring, third spring end on rear side of first baffle It is connect with collecting box bottom inside, so teacher contacts blackboard eraser wiping surface with pointed cone after teacher is finished blackboard eraser, and on Lower movement, can be such that the chalk dust on blackboard eraser falls in collecting box in this way, avoid the situation that chalk dust disorderly flies, the second bullet Spring is worked as a buffer when blackboard eraser wiping surface is contacted with pointed cone, after the chalk dust in collecting box reaches a certain level, teacher It is first pulled along first baffle, third spring is stretched, then is scanned out the chalk dust in collecting box out of collecting box with brush, and It is caught with sack or garbage basket, can effectively reduce dust pollution, after having swept, teacher looses one's grip and no longer pulls first baffle, and first Baffle sets back under the action of the spring force of third spring, can avoid chalk dust in this way and leaks out from first baffle.

Because further including having placing box, second baffle and handle, right support lower right side is equipped with placing box, placing box bottom It is provided with groove, lower end is provided with through-hole on the right side of placing box, and through-hole and groove are placed with second gear in same level in through-hole Plate, second baffle left end are located in groove, and second baffle right side central is equipped with handle, so when being only left some powder in placing box When nib can not reuse, garbage basket is first put into immediately below second baffle by teacher, then pull handle to the right, and handle drives second Baffle moves right, and then extracts second baffle out of groove out, and the chalk end in placing box can be fallen in garbage basket, when putting It sets in case when there is no chalk end, teacher pushes handle to the left again, and handle drives second baffle to be moved to the left, and then makes second baffle It is inserted into groove, then new chalk can be put into placing box by teacher.

The utility model has the advantages that the utility model passes through the left electronic reel of setting and right electronic reel, Teacher opens left electronic reel and right electronic reel, and left electronic reel and right electronic reel, which pass through drawstring, can drive meter Calculation is moved left and right with blackboard, is facilitated classmate while being appeared on the stage and practice, enhances practicability；Collecting box is set, can collected Sack is put in case, chalk dust can be fallen in the sack on collecting box, can effectively reduce dust pollution.

Detailed description of the invention

Fig. 1 is the schematic view of the front view of the utility model.

Fig. 2 is the part left view structural representation of the utility model.

Fig. 3 is the part schematic view of the front view of the utility model.

Wherein, the above drawings include the following reference numerals: 1: left support, 2: right support, 3: the first cabinets, 4: the second casees Body, 5: left electronic reel, 6: right electronic reel, 7: drawstring, 8: the first sliding rails, 9: the first sliding blocks, 10: the second sliding blocks, 11: Connecting rod, 12: it calculates and uses blackboard, 13: the second sliding rails, 14: third sliding block, 15: the first springs, 16: blackboard eraser, 17: handle, 18: sleeve, 19: second spring, 20: pointed cone, 21: collecting box, 22: first baffle, 23: third spring, 24: placing box, 25: recessed Slot, 26: through-hole, 27: second baffle, 28: handle.

Specific embodiment

Referenced herein embodiment is it is meant that a particular feature, structure, or characteristic described may include in conjunction with the embodiments In at least one embodiment of the utility model.The phrase, which occurs, in each position in the description might not each mean phase Same embodiment, nor the independent or alternative embodiment with other embodiments mutual exclusion.Those skilled in the art are explicitly Implicitly understand, embodiment described herein can be combined with other embodiments.

Embodiment 1

A kind of dedicated practice blackboard of primary school mathematics calculating, as shown in Figure 1-3, include left support 1, right support 2, the first case Body 3, the second cabinet 4, left electronic reel 5, right electronic reel 6, drawstring 7, the first sliding rail 8, the first sliding block 9, the second sliding block 10, connecting rod 11, calculating blackboard 12, the second sliding rail 13, third sliding block 14, the first spring 15, blackboard eraser 16 and handle 17, it is left Upper end is equipped with the first cabinet 3 between bracket 1 and right support 2, and lower end is equipped with the second cabinet 4 between left support 1 and right support 2, the Bottom left is symmetrically arranged with left electronic reel 5 on the left of one cabinet, 3 inner top and in the second cabinet 4, and 3 inner top of the first cabinet is right Bottom right is symmetrically arranged with right electronic reel 6 in side and the second cabinet 4, left electronic reel 5 with it is right on the electronic reel 6 in the right side Title is wound with drawstring 7, and bottom symmetrical is equipped with the first sliding rail 8,8 bottom of the first sliding rail of top in 3 inner top of the first cabinet and the second cabinet 4 The symmetrical slidingtype in portion and 8 top of the first sliding rail of lower section is connected with the first sliding block 9 and the second sliding block 10, and the first sliding block 9 is located at second It connects on the left of 10 left of sliding block, 7 end of left drawstring and the first sliding block 9, connects on the right side of 7 end of right drawstring and the second sliding block 10 It connects, connecting rod 11 is equipped between the first sliding block 9 and the second sliding block 10, is set between both up and down the first sliding block 9 and the second sliding block 10 There is calculating blackboard 12, the second sliding rail 13, the connection of 13 front side slidingtype of the second sliding rail are equipped at left and right sides of calculating blackboard 12 There is third sliding block 14, is symmetrically connected with the first spring 15 on the left of 14 right side of left third sliding block and right third sliding block 14, left and right Two the first springs of side, 15 end is equipped with blackboard eraser 16, and 16 front side middle part of blackboard eraser is equipped with handle 17.

Embodiment 2

A kind of dedicated practice blackboard of primary school mathematics calculating, as shown in Figure 1-3, include left support 1, right support 2, the first case Body 3, the second cabinet 4, left electronic reel 5, right electronic reel 6, drawstring 7, the first sliding rail 8, the first sliding block 9, the second sliding block 10, connecting rod 11, calculating blackboard 12, the second sliding rail 13, third sliding block 14, the first spring 15, blackboard eraser 16 and handle 17, it is left Upper end is equipped with the first cabinet 3 between bracket 1 and right support 2, and lower end is equipped with the second cabinet 4 between left support 1 and right support 2, the Bottom left is symmetrically arranged with left electronic reel 5 on the left of one cabinet, 3 inner top and in the second cabinet 4, and 3 inner top of the first cabinet is right Bottom right is symmetrically arranged with right electronic reel 6 in side and the second cabinet 4, left electronic reel 5 with it is right on the electronic reel 6 in the right side Title is wound with drawstring 7, and bottom symmetrical is equipped with the first sliding rail 8,8 bottom of the first sliding rail of top in 3 inner top of the first cabinet and the second cabinet 4 The symmetrical slidingtype in portion and 8 top of the first sliding rail of lower section is connected with the first sliding block 9 and the second sliding block 10, and the first sliding block 9 is located at second It connects on the left of 10 left of sliding block, 7 end of left drawstring and the first sliding block 9, connects on the right side of 7 end of right drawstring and the second sliding block 10 It connects, connecting rod 11 is equipped between the first sliding block 9 and the second sliding block 10, is set between both up and down the first sliding block 9 and the second sliding block 10 There is calculating blackboard 12, the second sliding rail 13, the connection of 13 front side slidingtype of the second sliding rail are equipped at left and right sides of calculating blackboard 12 There is third sliding block 14, is symmetrically connected with the first spring 15 on the left of 14 right side of left third sliding block and right third sliding block 14, left and right Two the first springs of side, 15 end is equipped with blackboard eraser 16, and 16 front side middle part of blackboard eraser is equipped with handle 17.

Further include having sleeve 18, second spring 19, pointed cone 20, collecting box 21, first baffle 22 and third spring 23, calculates With sleeve 18 is symmetrically and evenly equipped at left and right sides of 12 lower part of blackboard, rear side is equipped with second spring 19, second spring 19 in sleeve 18 Front end is equipped with pointed cone 20, and calculating blackboard 12 underside of forward bilateral symmetry is equipped with collecting box 21, and collecting box 21 is located under sleeve 18 Side, 21 front end rotary type of collecting box are connected with first baffle 22, and first baffle 22 and collecting box 21 cooperate, 22 rear side of first baffle Middle part left and right ends are equipped with third spring 23, and 23 end of third spring is connect with 21 bottom inside of collecting box.

Embodiment 3

A kind of dedicated practice blackboard of primary school mathematics calculating, as shown in Figure 1-3, include left support 1, right support 2, the first case Body 3, the second cabinet 4, left electronic reel 5, right electronic reel 6, drawstring 7, the first sliding rail 8, the first sliding block 9, the second sliding block 10, connecting rod 11, calculating blackboard 12, the second sliding rail 13, third sliding block 14, the first spring 15, blackboard eraser 16 and handle 17, it is left Upper end is equipped with the first cabinet 3 between bracket 1 and right support 2, and lower end is equipped with the second cabinet 4 between left support 1 and right support 2, the Bottom left is symmetrically arranged with left electronic reel 5 on the left of one cabinet, 3 inner top and in the second cabinet 4, and 3 inner top of the first cabinet is right Bottom right is symmetrically arranged with right electronic reel 6 in side and the second cabinet 4, left electronic reel 5 with it is right on the electronic reel 6 in the right side Title is wound with drawstring 7, and bottom symmetrical is equipped with the first sliding rail 8,8 bottom of the first sliding rail of top in 3 inner top of the first cabinet and the second cabinet 4 The symmetrical slidingtype in portion and 8 top of the first sliding rail of lower section is connected with the first sliding block 9 and the second sliding block 10, and the first sliding block 9 is located at second It connects on the left of 10 left of sliding block, 7 end of left drawstring and the first sliding block 9, connects on the right side of 7 end of right drawstring and the second sliding block 10 It connects, connecting rod 11 is equipped between the first sliding block 9 and the second sliding block 10, is set between both up and down the first sliding block 9 and the second sliding block 10 There is calculating blackboard 12, the second sliding rail 13, the connection of 13 front side slidingtype of the second sliding rail are equipped at left and right sides of calculating blackboard 12 There is third sliding block 14, is symmetrically connected with the first spring 15 on the left of 14 right side of left third sliding block and right third sliding block 14, left and right Two the first springs of side, 15 end is equipped with blackboard eraser 16, and 16 front side middle part of blackboard eraser is equipped with handle 17.

Further include having sleeve 18, second spring 19, pointed cone 20, collecting box 21, first baffle 22 and third spring 23, calculates With sleeve 18 is symmetrically and evenly equipped at left and right sides of 12 lower part of blackboard, rear side is equipped with second spring 19, second spring 19 in sleeve 18 Front end is equipped with pointed cone 20, and calculating blackboard 12 underside of forward bilateral symmetry is equipped with collecting box 21, and collecting box 21 is located under sleeve 18 Side, 21 front end rotary type of collecting box are connected with first baffle 22, and first baffle 22 and collecting box 21 cooperate, 22 rear side of first baffle Middle part left and right ends are equipped with third spring 23, and 23 end of third spring is connect with 21 bottom inside of collecting box.

It further include having placing box 24, second baffle 27 and handle 28,2 lower right side of right support is equipped with placing box 24, places 24 bottom of case is provided with groove 25, and 24 right side lower end of placing box is provided with through-hole 26, and through-hole 26 and groove 25 lead in same level Second baffle 27 is placed in hole 26,27 left end of second baffle is located in groove 25, and 27 right side central of second baffle is equipped with handle 28。

The utility model is mounted on front side of blackboard, and teacher inscribes mathematical computations in 12 left side of calculating blackboard, works as teacher When needing classmate to appear on the stage to practice, teacher starts left electronic reel 5 and right electronic reel 6 works, left electronic reel 5 Rope 7 is reeled, right electronic reel 6 puts drawstring 7, and then the first sliding block 9 and the second sliding block 10 is driven to slide to the left on the first sliding rail 8 Dynamic, calculating is moved to the left therewith with blackboard 12, and when calculating blackboard 12 is moved to the left predetermined position, teacher closes left electronic Reel 5 and right electronic reel 6, the first sliding block 9, the second sliding block 10 and the stopping of calculating blackboard 12 are moved to the left, then again Classmate is selected to be calculated in calculating with 12 right side of blackboard and blackboard right positions, after these classmates calculate, Lao Shizai The left electronic reel 5 of starting and right electronic reel 6 work, and left electronic reel 5 puts drawstring 7, and right electronic reel 6 reels rope 7, and then the first sliding block 9 and the second sliding block 10 is driven to slide to the right on the first sliding rail 8, calculating is moved right therewith with blackboard 12 Dynamic, when calculating blackboard 12 moves right to predetermined position, teacher closes left electronic reel 5 and right electronic reel 6, the One sliding block 9, the second sliding block 10 and the stopping of calculating blackboard 12 move right, and then select other classmates again in blackboard leftward position It is calculated, more classmates can be allowed to appear on the stage in this way and practiced, be also a kind of exercise to classmates, when needing to wipe blackboard When, teacher holds the handle 17 on blackboard eraser 16 and wipes, and calculating can be used with 12 right side of blackboard and blackboard right part Right blackboard eraser 16 is wiped, and left blackboard eraser 16 can be used to wipe with 12 left side of blackboard and blackboard left part calculating It wipes, when about 16 blackboard eraser wipes blackboard, blackboard eraser 16 drives the first spring 15 to move up and down, and then drives third sliding block 14 It is moved up and down on the second sliding rail 13, when blackboard eraser 16 is finished, blackboard eraser 16 is put into 12 lower part of calculating blackboard by teacher, this Sample, which will not influence classmate, to be practiced in calculating on blackboard 12.

Because further including having sleeve 18, second spring 19, pointed cone 20, collecting box 21, first baffle 22 and third spring 23, It calculates with sleeve 18 is symmetrically and evenly equipped at left and right sides of 12 lower part of blackboard, rear side is equipped with second spring 19, the second bullet in sleeve 18 19 front end of spring is equipped with pointed cone 20, and calculating blackboard 12 underside of forward bilateral symmetry is equipped with collecting box 21, and collecting box 21 is located at sleeve 18 downsides, 21 front end rotary type of collecting box are connected with first baffle 22, and first baffle 22 and collecting box 21 cooperate, first baffle 22 Left and right ends are equipped with third spring 23 in the middle part of rear side, and 23 end of third spring is connect with 21 bottom inside of collecting box, so working as After teacher is finished blackboard eraser 16, teacher contacts 16 wiping surface of blackboard eraser with pointed cone 20, and moves up and down, and can make blackboard in this way The chalk dust wiped on 16 is fallen in collecting box 21, avoids the situation that chalk dust disorderly flies, and second spring 19 is wiped in blackboard eraser 16 It wipes when face is contacted with pointed cone 20 and works as a buffer, after the chalk dust in collecting box 21 reaches a certain level, teacher is first drawn forward Dynamic first baffle 22, third spring 23 is stretched, then is scanned out the chalk dust in collecting box 21 out of collecting box 21 with brush, and It is caught with sack or garbage basket, can effectively reduce dust pollution, after having swept, teacher looses one's grip and no longer pulls first baffle 22, the One baffle 22 sets back under the action of the spring force of third spring 23, can avoid chalk dust in this way and leaks from first baffle 22 Out.

Because further including having placing box 24, second baffle 27 and handle 28,2 lower right side of right support is equipped with placing box 24, 24 bottom of placing box is provided with groove 25, and 24 right side lower end of placing box is provided with through-hole 26, and through-hole 26 and groove 25 are in same level On, second baffle 27 is placed in through-hole 26,27 left end of second baffle is located in groove 25, and 27 right side central of second baffle is equipped with Handle 28, so garbage basket is first put into second gear by teacher when being only left some chalk ends in placing box 24 can not reuse Immediately below plate 27, then pull handle 28 to the right, handle 28 drive second baffle 27 to move right, and then make second baffle 27 from recessed It is extracted out in slot 25, the chalk end in placing box 24 can be fallen in garbage basket, when there is no chalk end in placing box 24, Lao Shizai Handle 28 is pushed to the left, and handle 28 drives second baffle 27 to be moved to the left, and then is inserted into second baffle 27 in groove 25, so New chalk can be put into placing box 24 by teacher afterwards.

It should be understood that the embodiment is merely to illustrate the utility model rather than limitation the scope of the utility model.Furthermore It should be understood that after reading the content taught by the present invention, those skilled in the art can make the utility model various Change or modification, these equivalent forms also fall within the scope of the appended claims of the present application.

Claims (3)

1. a kind of primary school mathematics calculate dedicated practice blackboard, which is characterized in that include left support (1), right support (2), first Cabinet (3), the second cabinet (4), left electronic reel (5), right electronic reel (6), drawstring (7), the first sliding rail (8), first Sliding block (9), connecting rod (11), calculates and uses blackboard (12), the second sliding rail (13), third sliding block (14), first the second sliding block (10) Spring (15), blackboard eraser (16) and handle (17), upper end is equipped with the first cabinet (3) between left support (1) and right support (2), left Lower end is equipped with the second cabinet (4) between bracket (1) and right support (2), the first cabinet (3) inner top left side and the second cabinet (4) Interior bottom left is symmetrically arranged with left electronic reel (5), the first cabinet (3) inner top right side and the second cabinet (4) interior bottom, right Side is symmetrically arranged with right electronic reel (6), is symmetrically wound with drawstring (7) on left electronic reel (5) and right electronic reel (6), First cabinet (3) inner top and the second cabinet (4) interior bottom symmetrical are equipped with the first sliding rail (8), top the first sliding rail (8) bottom and Symmetrical slidingtype is connected with the first sliding block (9) and the second sliding block (10) at the top of the first sliding rail of lower section (8), and the first sliding block (9) is located at It is connect on the left of second sliding block (10) left, left drawstring (7) end and the first sliding block (9), drawstring (7) end in right is sliding with second Connection on the right side of block (10), is equipped with connecting rod (11) between the first sliding block (9) and the second sliding block (10), the first sliding block of both up and down (9) calculating is equipped between the second sliding block (10) with blackboard (12), calculating blackboard (12) left and right sides is equipped with the second sliding rail (13), slidingtype is connected with third sliding block (14) on front side of the second sliding rail (13), left third sliding block (14) right side and right third It being symmetrically connected with the first spring (15) on the left of sliding block (14), two the first spring of side (15) ends of left and right are equipped with blackboard eraser (16), Middle part is equipped with handle (17) on front side of blackboard eraser (16).

2. a kind of primary school mathematics as described in claim 1 calculate dedicated practice blackboard, which is characterized in that further include having sleeve (18), blackboard is used in second spring (19), pointed cone (20), collecting box (21), first baffle (22) and third spring (23), calculating (12) sleeve (18) symmetrically and evenly are equipped at left and right sides of lower part, rear side is equipped with second spring (19) in sleeve (18), second spring (19) front end is equipped with pointed cone (20), calculates and is equipped with collecting box (21) with blackboard (12) underside of forward bilateral symmetry, collecting box (21) On the downside of sleeve (18), collecting box (21) front end rotary type is connected with first baffle (22), first baffle (22) and collecting box (21) cooperate, middle part left and right ends are equipped with third spring (23) on rear side of first baffle (22), third spring (23) end and receipts The connection of header (21) bottom inside.

3. a kind of primary school mathematics as claimed in claim 2 calculate dedicated practice blackboard, which is characterized in that further include having placing box (24), second baffle (27) and handle (28), right support (2) lower right side are equipped with placing box (24), and placing box (24) bottom is opened Fluted (25), placing box (24) right side lower end are provided with through-hole (26), and through-hole (26) and groove (25) lead in same level It is placed with second baffle (27) in hole (26), second baffle (27) left end is located in groove (25), in second baffle (27) right side Portion is equipped with handle (28).