Your home's a hotspot for devising low-cost science fair projects. For instance, heading to the kitchen -- with an appetite for ideas, not food -- could help spark thoughts for the next affordable experiment.
Why? Because you probably own the majority of materials you need.
Try dedicating a portion of your family's weekly produce to a project to measure in which settings (fridge, counter or in a paper bag) fruit ripens the fastest and why [source: USDA]. Chemistry underlies cooking and baking, which also creates opportunities for experimentation. Several projects involve things lying around the kitchen, including measuring cups, glassware, salt, baking soda and flour. Just make sure you keep experiments nontoxic if you plan to reuse dishware.
Your child can also draw inspiration from the backyard or the local park, where the presence -- or lack thereof -- of certain plants and wildlife may warrant study.
The last tip for low-cost projects requires an observant mind, above all.