Despite the greatest strides in mathematics, these hard math problems remain unsolved. Take a crack at them yourself.

Students often struggle to connect math with the real world. Word problems—a combination of words, numbers, and mathematical operations—can be a perfect vehicle to take abstract numbers off the page.

For all of the recent strides we’ve made in the math world, we’re forever crunching calculations in pursuit of deeper numerical knowledge. Some math problems have been challenging us for centuries—but ...