If you put 'deer' in the search box at the very top of the page, you'll find numerous threads where a similar question has been asked.
On this thread:
http://www.gardenersworld.com/forum/problem-solving/hungry-deer-2/1933.html
two people said that they had tried Grazers spray, and found it successful. However, that is sprayed on the plants, and makes them taste unpleasant to the deer. I wouldn't like to eat any vegetables that had been sprayed.
Chili powder might be worth trying. You could have some sacrificial crops dusted with chili, for the deer. Hoping that once the deer have tasted them, they don't get onto the undusted crops.
Some people say that wire netting, laid flat on the ground, creates a barrier that deer do like to step on.
Alternatively, you could get hold of a motion-sensitive night-time wildlife camera, local wildlife enthousiasts will have such devices, and take some photos or film, of the deer in action. That might be a fun thing for kids to do. This is not a very good snap, but shows you the idea...