School life is an obvious starting point when looking for problems to solve. Third-grade students can think about what parts of their day are hard, annoying or inefficient and begin brainstorming ways to make things better. Think about smarter ways to track homework assignments, carry books and materials, avoid bullies, stay in touch with friends or understand lessons. Even simple activities can inspire ideas, like a water fountain attachment that adds flavor and nutrition as water flows through it.
Third-graders also face challenges and chores at home. Turn them into a source of inspiration. A quick analysis of difficult moments in home life could start to present such ideas as self-removing garbage, a spill-proof cup (or table), beginner's chopsticks or the stink-free bathroom of the future. Remember that improving life by adding beauty or fun is also a viable form of invention. Students can find ways to spice up life at home, such as ceiling fan animations or an attractive new fishbowl design.
The environmental and social problems that plague the world may seem out of reach for a third grader. However, many world-scale problems have effects on individual homes and neighborhoods, and this can give a student the conceptual foothold needed to help him start developing a solution. An elegant and inexpensive solution that helps one household reduce waste, save energy or live a healthier life can spread to other homes and start making a real difference in the world.
Pets bring pleasure, companionship, work and expense. Since many third graders are involved in the care and feeding of their pets, it is an area where they may have a vested interest in improving the processes your family uses. Inventions like an auto-timed pet feeder or a plumbed cat toilet can reduce the time and effort spent on basic pet care. Another possibility is inventions that cut down painful or unpleasant pet interactions, like a scratch guard, breath mints for dogs or a yank-proof leash.