Those were great! I'm pretty good at doing math in my head and my brain still visualizes numbers and their relationships based on lengths and colors. In 1970s Sweden they were called "tiostavar", "ten-sticks". They were made of high quality painted wood and very tactile and pleasant to work with. The lengths were precise so they would add up properly in any combination, and the widths were equal to one unit of length so you could make areas and volumes.

(Edit) like these: https://orsjoforskoleklass.files.wordpress.com/2014/11/img_3...

My early education used sticks and cubes like that. I don't remember different lengths with different colors, but that makes a lot of sense as a way to teach addition.

The 1000-cube fascinated me. I think the classroom only had one of them, so the teacher kept it, and we never really got to use it (and it was hard to gather 10 100-squares to build your own).

that looks interesting! it engages a lot of senses, trying now to google for something like that on amazon, but maybe i can print those myself with a 3d printer. or, maybe someone has open sourced a design for those cubicles already?

found the ones I used: http://store.mathusee.com/catalog/math-u-see/manipulatives/i...