USES FOR CHALK

• A Source of Calcium- As it's scientific name suggests, calcium carbonate has calcium with a chance of casein, a milk protein. Those how don't like to drink milk or can not may have the urge to eat chalk for their calcium deficiency.  
  
• Art- Chalk can also be a good medium for art. Either it's on black construction paper, light marking for sculptures or street art. Chalk can create beautiful 3-D art with the side walk as it's canvas. There is a video below showing so. (Peteris Kelle, 2013)

There are many ways of using chalk. Some of the more generic uses include writing of the classroom blackboard, marking where certain components are in construction or dusting on to your hands for a better grip, like in gymnastics. 
Chalk is ideal for all these things due to it's low toxicity, dry texture and easily-washed-away feature.

However there are much more clever uses for chalk. This includes:

• Stopping Ants In Their Tracks- If you draw lines around door and window, ants won't cross the line. Theory is that ants don't want the dust stuck to their feet or they hate calcium carbonate. Either way, it works.
• Removes Greasy Stains- The absorbency tendency of chalk allows it to remove or help remove stains when rubbed over an effected area. Letting your clothes sit with chalk on them for ten minutes will remove most stains.
• Rust Prevention- As said before chalk absorbs moisture, therefore placing a few chalk sticks in a toolbox can deter the chances of rusting. This is also true for keeping the colour of silver for your silverware, plates, etc.
• Nail Cleaner- Rubbing chalk on a nail file or brush and then cleaning you nails, reapplying when needed gets rid of dirt and evens out your nails.

(Clever Uses For,2014)