Ben Franklin and His Magic Squares
The first half of this reader written for 2nd/3rd grade level tells you about Ben and his rather colorful life. It's a well-done historical sketch that all of my kid enjoyed as a readaloud (5, 7 and 9 at this time). Then, after setting the stage for you that this is one busy, colorful guy full of ideas, they tell the story (probably a myth) of Ben falling asleep during a government session and turning to doodling and math puzzles to overcome his boredom.
Nice reader to explore history and math mysteries using math facts.