Using relates to Textbook m on mathematics and can be used in higher education institutions x at studying numerical rows theory. The aim of the invention is illustrative understood third term of partial sums, convergence, divergence and comparing numerical signs znakopolozhitelnyh rows. Summary of the Invention in representatively bottom posobii comprising a frame with spaced inside discs contacting each other and with the inner periphery of frame with their cylindrical surfaces, the frame is in the form of an isosceles brackets and wheels are made with different diameters in a elektroplafonov embedded in the contact circuit a control panel containing individual for each zlekgroplafona normally open and common keys. The discs have the same thickness equal to the height corner flanges at the ends and the apex of which, and the centers of disks made blind holes, with their detachable attachment compounds for demonstration board. All the elements are color display. Allowance has three identical plates with numbers identical mounting holes in their upper parts with the possibility of attaching plates on the facial surface of the disc. Setting s corner wheels in sequence exhibit convergence, divergence and signs comparison. Z.p.f 3-ly. 2 yl. Yo
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