Friday 19 February 2021

Week 8 of the count up

8


This week I’m using the fact that 4 + 4 = 8.

Pick any 4-digit number (it must contain at least 2 different digits, so it could be 4985, or 5583 etc but not 5555)

1.     Write the digits in ascending order e.g. 4985 would become 4589

2.     Now write the digits in descending order e.g. 4985 would become 9854

3.     Now subtract the smaller number from the larger e.g. 9854 minus 4589 equals 5265

Now start again at 1 with this new number, and eventually you will end up with 6174, no matter where you start. The number 6174 is known as Kaprekar’s constant

 

For an explanation of why this is a countUP and not a countDOWN, CLICKHERE for the New Year post

No comments:

Post a Comment

Thank you for reading the blog! Because of spam, we have to approve comments on older posts, which we will do as quickly as we can (message to spammers: Jack will escort you to the airlock and send you on your way with a well-placed hoof). Jack and Melodie love comments and try to respond to them all.