Centesimal frame montessori measure instrument for laser or cnc

instrument measure the percent of circle fraction montessori for laser engraver and cnc router

Montessori centesimal frame divided into 100 percent, the white line corresponds to the 0 mark and to 100

used with Fraction Circles cut out labeled https://www.thingiverse.com/thing:2828126
and with fraction circles https://www.thingiverse.com/thing:2839103