1) why do we add salt to the ice?
to decrease the temperature
2) why do we add the cookies and other things, only after the milk has frozen slightly
otherwise, it will melt together with the milk while it's tending to freeze.
3) what are two factors that affect the freezing you think?
4) why do you need a bit of air in the bag?
To help it to move forward and backward.(easier to move)