Learning Resources Rainbow Pentominoes. Primary learners can get hands-on with geometry with these Rainbow Pentominoes. Set of 72 pentominoes are a great primary maths resource as children develop their understanding of properties of shape. Scored to show the individual squares, this set features 6 colours (red, blue, green, yellow, orange and purple). Includes activity guide to aid learning. Includes useful storage tub for learning. Pentominoes measure up to 7.5cm L. Suitable for ages 6+.