# Arithmetic rope

 Arithmetics Addition X + Y = Z X knots are counted, then another Y. The total number of counted knots is Z. e.g.: 5 + 4 = 9 Subtraction X - Y = Z X knots are counted, then Y knots are 'uncounted'. The total number of knots remaining counted is Z. e.g.: 9 - 4 = 5 Multiplication X * Y = Z X knots are counted, and the resulting distance is put together Y times. The total number of counted knots is Z. e.g.: 4 * 3 = 12 Division X / Y = Z (remainder Q) X knots are counted. From these knots, Y knots are taken and grouped together until all are used up. The number of groups is Z; the number of remaining knots represents the remainder, Q. e.g.: 12 / 4 = 3 Geometrics Right angle The two ends of the knotted rope are nailed together, and 5 knots are counted for the base. For the perpendicular side, 4 knots are required. The right-angled triangle is generated by pulling the sides taut. Equilateral triangle The two ends of the knotted rope are nailed together, and 5 knots are counted for each side. The sides are tautened to create an equilateral triangle. Circle One end is nailed down, and a stylus is attached at the desired distance. With the rope pulled taut, the stylus is moved around, forming a circle.