• Home
  • About
  • Contact
  • Sitemap
  • Converter
  • Calculator
  • HowTos
  • Topics

Articles from June, 2009

Decimal/Binary Conversion Table

By Rick Regan Contact e-mail icon (Published June 30th, 2009)

Here is a table you can use to convert small integers — integers between 0 and 255 — directly between decimal and binary (as an alternative to using a decimal/binary converter):

Continue reading …

Nines in Binary

By Rick Regan Contact e-mail icon (Published June 10th, 2009)

I discovered a cool property of positive integers of the form 10n-1, that is, integers made up of n digits of 9s: they have binary representations that have exactly n digits of trailing 1s. For example, 9,999,999 in decimal is 100110001001011001111111 in binary.

The property is interesting in and of itself, but what is more interesting is the process I went through to discover it. It’s a small-scale example of experimental mathematics: I observed something interesting, experimented to collect more data, developed a hypothesis, and constructed a proof.

Continue reading …


Subscribe

RSS feed icon
Get articles by RSS (What Is RSS?)
RSS e-mail icon
Get articles by e-mail

Featured Articles

  • Elements of Binary in the NCAA Basketball Tournament

    Is it basketball or binary?

  • What a Binary Counter Looks and Sounds Like

    See and hear the symmetry in binary counting.

  • Visualizing Consecutive Binary Integers

    Binary numbers in black and white.

  • Seeing Powers of Five in Powers of Two and Vice Versa

    2-3 = 0.125 and 53 = 125 -- why do they look similar?

Most Popular Articles

  • Java Hangs When Converting 2.2250738585072012e-308

    Java's decimal to floating-point conversion can lead to a DoS attack.

  • PHP Hangs On Numeric Value 2.2250738585072011e-308

    PHP's decimal to floating-point conversion can lead to a DoS attack.

Articles by Category

  • Powers of two
  • Binary numbers
  • Binary code
  • Binary logic
  • Numbers in computers
  • Background math

Articles by Tag

Algebra Binary-coded decimal Binary arithmetic Binary integers C Code Convert to binary Convert to decimal Convert to hexadecimal Decimals Education Exponents Floating-point Fractions Geekware Geometric series Java Modular arithmetic Pascal's triangle PHP Pop culture Proof

Articles by Date

  • January 2012
  • December 2011
  • November 2011
  • October 2011
  • September 2011
  • August 2011
  • July 2011
  • June 2011
  • May 2011
  • April 2011
  • March 2011
  • February 2011
  • January 2011
  • December 2010
  • November 2010
  • October 2010
  • September 2010
  • August 2010
  • July 2010
  • June 2010
  • May 2010
  • April 2010
  • March 2010
  • February 2010
  • January 2010
  • December 2009
  • November 2009
  • October 2009
  • September 2009
  • August 2009
  • July 2009
  • June 2009
  • May 2009
  • April 2009
  • March 2009
  • February 2009
  • January 2009
  • December 2008
  • November 2008

Latest Articles

  • Binary Addition
  • Bigcomp: Deciding Truncated, Near Halfway Conversions
  • Exploring Binary: One Million Views
  • Using Integers to Check a Floating-Point Approximation
  • strtod()’s Initial Decimal to Floating-Point Approximation
  • Fast Path Decimal to Floating-Point Conversion
  • Why Powers of Ten Up to 1022 Are Exact As Doubles
  • Correct Decimal To Floating-Point Using Big Integers
  • Binary Numbers Haiku
  • How I Taught Third Graders Binary Numbers

Powered by WordPress

Copyright © 2008-2012 Exploring Binary