The author in this paragraph is talking about copper pennies which were minted during a time when copper was very limited due to World War II and pennies which were mistakenly doubled stamped in 1955.
It talks about how only few copper pennies were minted in 1943 due to need of coppers in World War II. Today it has become very rare to see copper pennies minted in 1943 as pennies were mostly minted out of steel during that time. The price for these copper pennies minted in 1943 as well as the 1955 double die penny, pennies which were mistakenly double stamped, are as high as $25,000 because of its interesting history and rarity.
Thus, the title "Pennies Worth Thousands" is the best title for this paragraph as these pennies can fetch thousands of dollars for a single penny.
The laughing man in the book When You Reach Me seems crazy because he practices punches to save Sal from getting run over by a truck. The laughing man in reality was Marcus (the kid who tries to explain to Miranda the concept of time travel) traveled back in time.
