This extension set of Algebra Pieces introduces the concept of a second unknown variable "Y". Have your students explore the world of X and Y variables in a hands-on manner. Set includes 40 pieces: Y (10 x 36 mm) - 10 red and 10 blue XY (36 x 53 mm) - 5 red and 5 blue Y2 (36 x 36 mm) - 5 red and 5 blue. To be used with our original Algebra Pieces 20900 (Blue and Red Pieces). Made in India. 🇮🇳