Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
One example is below.
Q: In 1582 the united provinces invited francis, duke of anjou to lead them; but after a failed attempt to take antwerp in 1583, the duke left the netherlands again. after the assassination of william of orange (10 july 1584), both henry iii of france and elizabeth i of england declined the offer of sovereignty. however, the latter agreed to turn the united provinces into a protectorate of england (treaty of nonsuch, 1585), and sent the earl of leicester as governor-general. this was unsuccessful and in 1588 the provinces became a confederacy. the union of utrecht is regarded as the foundation of the republic of the seven united provinces, which was not recognized by the spanish empire until the peace of westphalia in 1648.
A: In what year did francis, duke of anjou leave the netherlands?
Rationale: The generated question is perfect. Because the question is based on second sentence of the input passage and its answer is 1583.
Q: New research shows how kids' brains reorganize as they learn math. All the time you spent memorizing multiplication tables may have made you a better mathematician, according to a new study. A team of scientists from Stanford University, in California, have shown how the brain reorganizes itself as kids learn math. After a certain amount of time spent practicing math, kids can put away the calculator . They don't even need to count on their fingers. They simply know the answers to subtraction , addition, and multiplication facts. The quicker kids can recall basic math facts, the easier it is for them to solve more complicated math problems. The Stanford University researchers observed the brain activity of 28 students aged 7to 9 for the study. They took scans of the students' brains as the students solved math calculations without the help of a calculator, pen or paper. A calculation--three plus four equals seven, for example--flashed on a screen. The students pushed a button to say if the answer was right or wrong. The scientists also recorded the response speed, and what parts of the brain became active as the kids pushed the button. These observations showed a process called fact retrieval . Rather than using their fingers to count, or writing out answers on a piece of paper, the students pulled the answers from memory. It's as if the answers to basic math problems are kept in a long-term storage area in the brain, which was built from repetition. "Experience really does matter," said Dr. Kathy Mann Koepeke. Children make the shift from counting to fact retrieval when they are 8 to 9 years old, the study shows. This is the time when most students are learning basic addition and subtraction. When kids have basic math facts memorized, the brain has more free space to learn more complicated math. This process has benefits for the future. The study shows as kids grow older, their answers rely more on memory and become quicker and more accurate. Less brain activity is devoted to counting. Some children make this shift quicker than others.
A:
What plays a key role in solving a math problem?