"down to earth problem" is correct and usable in written English.
It is usually used to refer to a problem that is familiar, practical, and accessible. For example: "The professor asked us to solve a down to earth problem involving the economic recession."
Now, origami engineers Zhong You and Weina Wu of the University of Oxford in the United Kingdom have tackled a more down-to-earth problem: whether a tall shopping bag built from a rigid material or an open-topped cardboard box could ever be folded flat like a traditional grocery bag without having to open its bottom.
After all, our brains evolved to help us solve down-to-earth problems of survival and reproduction; there is no particular reason to assume they should be capable of cracking every big philosophical puzzle we happen to throw at them.
The $65 million show, held up in the past by trouble with its ambitious flying effects and the safety issues they posed, is struggling now with much more down-to-earth problems: adding a major final number and straightening out some plotting and dialogue preview audiences baffled.
For Sierra-Sastre, whose scientific background includes chemistry, nanotechnology, and materials science, this means a rewarding job where she can contribute to securing the U.S. economy and apply her scientific knowledge to complex down-to-earth problems.
For Southwest as a company, it's dumb for an airline that brands itself as a down-to-earth, problem-solving company to hand brand control over to the annoying practices of Chase Visa.
In recent months, such lofty goals have been brought down to earth by food and product safety problems involving Chinese imports.
When asked what would make a professional more appealing participants felt they should be "down to earth" (eg. "not use big, medical words"), non-judgemental and have experienced a mental health problem themselves.
Seemed very down to earth".
He seems honest and down to earth".
