3 ms·

Admittedly it's quite dramatic when 45 minutes into the movie, Cole forgets whether he's on 2^42 or 2^43 and has to start over.

• kccqzy 4y ago
  In elementary school having just learned exponentiation several friends of mine and I challenged each other to see who could find 2^64 the fastest. Two among the group independently discovered the classic exponentiation-by-squaring method, even though none of us could prove it right. Cole definitely would not have multiplied by two repeatedly.
  • madcaptenor 4y ago
    For some reason, the first method that came to mind for me was to find 2^60 as (1000 + 24)^6 (or at least I thought it would be until I realized finding powers of 24 wasn't that easy) and then double that seven times. I would guess that Cole found 2^67 by multiple methods, because obviously it would be tragic if it turned out he was factoring the wrong number.
  • Someone 4y ago
    He also would have known the final decimal digit of powers of 2 (starting at 2^1) is 2, 4, 8, 6, 2, 4, 8, 6, 2, 4, 8, 6… So, 2^42 ends with the same digit as 2^38, 2^34, …, 2^2, so its last digit is a 4.