The invention relates to the technical field of teaching assistance, in particular to an auxiliary device for mathematics teaching, which comprises a supporting frame, a supporting plate is fixedly connected to the outer side of the supporting frame, a positioning box is fixedly connected to the bottom of a supporting column, a distance adapting
assembly for adjusting the distance is arranged on a connecting frame, and a telescopic arm and a
ratchet wheel are arranged in the distance adapting
assembly. Through cooperation of a distance adapting
assembly, a self-locking assembly and a self-elastic assembly, when a circle is drawn on the drawing plate, a holding rod is rotated, the
ratchet wheel is driven to rotate intermittently, then a threaded strip is driven to rotate, the telescopic arm is moved through cooperation teeth, and the drawing
radius is adjusted; the drawing pen is always vertically attached to the
drawing board, the situation that when a
compass type auxiliary device inclines in use, friction between a blackboard and the drawing pen is increased, operation is not smooth, and particularly when multiple sets of circles with different radiuses need to be drawn, time is wasted when the radiuses are adjusted is avoided, and the efficiency of mathematics teaching is improved.