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Seattle Seventh Grader Wins National Math Bee (ap.org)

Posted by msmash on from the these-kids-get-math dept.

Edward Wan, a Seattle-based seventh grader has won the national math bee. Wan, who studies at Lakeside Middle School, beat 224 other middle school students nationwide to win the 2016 Raytheon Mathcounts National Competition. From an Associated Press report: Competition officials said in a news release the 13-year-old won the final round by answering the question, "What is the remainder when 999,999,999 is divided by 32?" Wan gave the correct answer of 31 In just under seven seconds.Deadspin reports about the live streaming of the event: Today's Mathcounts national championship for middle-school mathletes aired on ESPN3, and it was definitely the best live sports anyone could be watching at 10 a.m. on a Monday morning. We couldn't agree more.

5 of 106 comments (clear)

  1. Quick kid by TheEmptySet · · Score: 5, Informative

    Maths is about understanding something the right way. And I'm guessing this kid did not take the seven seconds to do anything complicated. He just factored 32. i.e. 2^5. Then noticed that 999,999,999 + 1 = 1,000,000,000 = 10^10 = 2^10 * 5*10 which clearly contains a factor of 2^5. So 32 goes into 1,000,000,000. So the remainder after division of 999,999,999 by 32 is 31. I think you need about 2 seconds for that once you realise the correct way to think about it. So he took 5 seconds to work out what he should do. Quick kid!

    1. Re:Quick kid by Opportunist · · Score: 3, Insightful

      He probably did what I have done at that age. 1,000,000,000 by 32 is 500,000,000 by 16 is 250,000,000 by 8 is 125,000,000 by 4 is 62,500,00 by 2 is ...doesn't matter but it is divisible without remainder. So one less means that 31 must be left.

      --
      We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
  2. I'm shocked! by Locke2005 · · Score: 3, Funny

    Hey, great way to dispel those stereotypes, Wan!!! Keep it up!

    --
    I've abandoned my search for truth; now I'm just looking for some useful delusions.
  3. Solvable in 1 second. by sconeu · · Score: 4, Informative

    10^n is evenly divisible by 2^n

    Therefore 999,999,999 = 10^9-1. Therefore the remainder is -1 mod 32 which = 31.

    --
    General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
  4. Re:Asian privilege by ShanghaiBill · · Score: 4, Interesting

    When you get to the 999,999,999/13 part ...

    It is 999,999,999/32. The 13 is his age. The problem is not so hard. 1,000,000,000 is 10^9 = 2^9*5^9, and 32=2^5, so obviously 1,000,000,000 is evenly divisible by 32, so one less is going to have a remainder of 31. Duh.

    I don't know much about the Math Bee, but I coach kids for the Math Olympiad, and we do a lot of drills to break numbers down into prime factors, and rapidly compute powers of two. Solving a problem like this in seven seconds is impressive, but not uncommon for a kid that has been trained.