### Not a Polite Question

When asked how old she was, the teacher replied: My age in years is not prime but odd and when reversed and added to my age you have a perfect square...

### Whole Numbers Only

Can you work out how many of each kind of pencil this student bought?

# Slippy Numbers

##### Stage: 3 Challenge Level:

Well done all those people who found the slippys ending in 2 and 3. How about slippy 4? That's a small one you can find quickly! Here is the best explanation of the process from Yeow Seng Poo, River Valley High School, Singapore:

I multiply the last digit of the slippy number, namely 2 or 3, by itself to get the last digit of the multiplied number that is also the second last digit in the slippy number. I then repeat the process with each of the digits, adding any tens produced during the multiplication of one digit to the next digit before continuing.

This continues till I reach an answer of 1 with no tens to bring over to the next possible digit, this is the answer. The last part is due to the fact that the first digit of the slippy number has to be one in order for the multiplied number to begin with 2 or 3.