"Leave no stone unturned" can be found on page 6 of "The Phantom Tollbooth" by Norton Juster.
Milo, the protagonist in "The Phantom Tollbooth," is around 10 years old. His exact age is not specifically mentioned in the book.
It is in episode 6 Tetsusagia, The Phantom Sword
Gaston Leoux's Phantom of the Opera Chapter 1-3 The Phantom demands his seat Box 5 Christine remembers Raoul and she falls in love with his brother Phillippe. Chapter 5-6 Phantom whispers to her in sleep that he can make her a star. Phillippe is killed by the Phantom. She comforts Raoul they remember their childhood memories. Chapter11 the Phantom makes himself known carry Christine to his lair.
The long math problem in "The Phantom Tollbooth" involved Milo, the protagonist, trying to figure out the area of the Dodecahedron's brother. The problem involved complex calculations that required abstract thinking and problem-solving skills. It emphasized the importance of creativity and critical thinking in approaching mathematical challenges.
Awkward Embraces - 2010 The Flashback 2-6 was released on: USA: 8 April 2011
Hotel - 1983 Flashback 1-6 was released on: USA: 9 November 1983 Netherlands: 13 February 1985
Friends - 1994 The One with the Flashback 3-6 was released on: USA: 31 October 1996 Portugal: 10 October 2005
Chapter 1: Shotgun Cheatman's Last Night Above Ground Chapter 2: The Mouse in the Milk Chapter 3: A One-Woman Crime Wave Chapter 4: The Day of Judgement Chapter 5: The Phantom Brakeman Chapter 6: Things with Wings Chapter 7: Contennial Summer Chapter 8: The Troop Train Glad I could help, but if I say so myself, this book was AWFUL! It's not one I recommend reading.
Friends - 1994 The One with the Flashback 3-6 is rated/received certificates of: Argentina:Atp Hungary:12 Mexico:B Netherlands:AL USA:TV-PG
Chapter 6 of what Book?
World's Worst Director - 2012 World's Worst Flashback 2-6 was released on: USA: 12 May 2013