The term educational toys has been so over used it's lost its meaning. Anything with the slightest value can be called educational. What proponents of play/creativity really mean when they think of educational toys (open-ended, etc.) is "design toys."
A design toy is different than an educational toy. Toys that are used to design with (Lego®, Zometool®, Kaleidograph®, K'nex®, Color Cubes ... to name a few), allow us to create new designs and structures. These products are not merely "toy designs" or simply "designed" for consumers, they are tools used for designing. Most blocks are time-honored design toys, but different materials offer different possibilities. All design toys find their origins in the Froebel Gifts. These are also arguably the world's first educational toys.
There were some educational materials prior to Froebel (like ABC blocks) but they were limited and didactic. Froebel organized a system of materials that provides significant educational value for learning math/science, building language, and boosting creativity. Basic unit blocks and toys such as Tinkertoy®, Lincoln Logs, Cuisenaire® Rods, etc. all point back to the Froebel Gifts.
Referring to Froebel Gifts as "the world’s first educational toys" may add some trust/cachet but it can also make them sound old fashioned and out-of-date. In truth this misses the modern appeal of toys that encourage design … because design is the new career path for the 21st century. In design education terms, the Froebel Gifts offer "design challenges," and they reflect the same process modern business uses in challenging their workforce to design new and better solutions to problems.