if you move the leading digit to the units place of a number, i.e. 72 becomes 27 or 381 becomes 813, the original number is a factor or multiple of the new number? Oh, and not all digits are identical.

- Can you find a two digit number that will work in this way?
- If you can't, was it because it can't happen?
- In his tweet, James Tanton claims that there are no three or four digit digit numbers that will work. He doesn't make a statement like that unless he has found some way to show it NEVER works. Can you find that rule?

```
There is no three-digit number abc divisible by bca. (Move first digit to end) No 4-digit number abcd divisible by bcda. Five? Six?
```

— James Tanton (@jamestanton) April 26, 2014

## No comments:

## Post a Comment