Baking soda can remove tartar from your teeth as long as the tartar is not too severely built up on your teeth.
To use baking soda to remove tartar from your teeth get a toothbrush wet and then sprinkle some baking soda onto the wet toothbrush.
Then brush your teeth so that the baking soda gets onto your teeth.
Then allow the baking soda to remain on your teeth for 10 minutes or so.
Then get some more baking soda onto a toothbrush and brush your teeth again.
Next rinse your teeth and mouth out with some water or mouthwash.
It might take a few tries to brush your teeth with the toothbrush to get the tartar off your teeth but it will work just fine.