With these building blocks, children will playfully learn to count to 10. The blocks feature lovely illustrations from the Sailors Bay collection. Can you point out the seagull, sailboat and pelican? You can stack the blocks to build a tall tower, or put them on the floor horizontally. The little blocks can be placed inside the bigger ones, so they're easy to tidy. The blocks are made of sturdy cardboard, so they're very durable. The smallest block measures 5 cm, and the biggest is 14 cm.