The Kaprekar constant 6174

In the mysterious 495, (1) we chose any 3-digit number, (2) arranged the digits in decreasing order forming the largest integer,  (3) arranged the digit in increasing order forming the smallest integer, and (4) subtracted the smaller from the larger. Each time a difference is obtained, we repeated steps 2-4 several times and we ended up having 495. We explained the mystery behind this ‘phenomenon’ and we were quite fascinated.

In this post, we examine the 4-digit Kaprekar constant. That is, if the digits of a 4-digit number are not all equal, there is a certain number that we will end up with if we repeat the enumerated process above. Let’s have an example. » Read more

Top 20 Mathematics Posts for 2011

It’s year end again and it’s time for our year end summary. Here are the top 20 mathematics articles written in 2011.

  1. The \epsilon-\delta proof: Example 1
  2. 10 Ways to Think Like a Mathematician
  3. Math Exercises, Problems, and Investigations
  4. Introduction to Mathematical Proofs
  5. Arithmetic Sequences and Linear Functions
  6. Paper Folding: Locating the square root of a number on the number line
  7. Generating Pythagorean Triples from Square Numbers
  8. Finger Multiplication
  9. Simon’s Favorite Factoring Trick
  10. The Handshake Problems and Its Multiple Solutions
  11. Operations on Integers – Subtraction
  12. Platonic Solids: Why only five of them?
  13. The Commutativity of Real Numbers
  14. Why Finger Multiplication Works
  15. Order of Operations: 360 or 354?
  16. The mystery of 495 explained
  17. Irrational Numbers as Decimals
  18. Experimental and Theoretical Probability 5
  19. Equation of a line: The derivation of y = mx + b
  20. Discovering multiplication of integers through patterns

Enjoy reading!

September 2011 Week 1 Posts Summary

Mathematics and Multimedia

My Other Blogs
1 2 3