Jumbo Unifix Cubes PreK Math Kit Build early math skills with this collection of activities to use with our chunky Jumbo Unifix Cubes. Little hands will have fun sorting, counting, comparing and building! Along the way children will develop critical early math skills. Set includes 20 Jumbo Unifix Cubes, 6 Memory Activity Cards, 4 Pattern Activity Cards and 22 Number Cards 1–20. Perfect for small group play at school or fun at home.