In 1771, misfortune struck Euler again, when a cataract in his left eye robbed him of his sight entirely. Incredibly, this did not seem to slow him at all. In fact, during his remaining thirteen years, his publishing output accelerated. Of the 886 books and articles he produced in his lifetime – on topics including mathematics, philosophy, mechanics, electricity, astronomy, optics, and music – half of them were completed after total blindness! Use the drop-down menus to complete the statements about Euler's life after he lost his sight.

After the cataract took Euler's sight, he

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About how many books and articles did Euler complete after he lost his sight entirely?

Why did Euler enter the Paris Academy of Sciences Prize Problem competition?

He wanted to become a scientist.
He wanted to build a ship.
He wanted to become a sailor.
He wanted the mathematical challenge.