Chalk It is formed in the sea by sub-microscopic plankton, which fall to the sea floor and are then consolidated and compressed during diagenesis into chalk rock. Most people first encounter the word "chalk" in school where it refers to blackboard chalk, which was originally made of mineral chalk, since it readily crumbles and leaves particles that stick loosely to rough surfaces, allowing it to make writing that can be readily erased. Blackboard chalk manufacture now may utilize mineral chalk, other mineral sources of calcium carbonate, or the mineral gypsum (calcium sulfate). While gypsum-based blackboard chalk is the lowest cost to
Blackboard Inc. the deployment options of Blackboard Learn to include public cloud, and improvements to Blackboard's mobile app. , Blackboard serves approximately 17,000 schools and organizations. It holds the highest share of the education market with 75 percent of colleges and universities and more than half of K-12 districts in the US using its products and services. , Blackboard had acquired MyEdu, Perceptis, and CardSmith, and Requestec under Bhatt's leadership. The acquisitions reflected Bhatt's new acquisition strategy of making investments that serve students and will lead to innovations in Blackboard's core teaching and learning products. Blackboard has used the acquisition of other