Complete circles with these Curve Blocks. Children will learn about ordering, spatial relations, and how to compare the height and size of each circle. This elegant learning tool deserves a spot in any preschool class or young learners' playroom. As with all Plan Toys, Curve Blocks are made using ethically-produced, all-natural rubberwood and non-toxic water-based paints to create a perfect blend of beauty and function. p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 15.0px Calibri; -webkit-text-stroke: #000000} span.s1 {font-kerning: none} WARNING: CHOKING HAZARD – small parts. Not for children under 3 years.