# Count On

## Explorer

#### Even Today is Unusual!

2nd February 2000 is an unusual date. Why? Because 2/2/2000 is made up of only even digits.

An even number is one that is a multiple of 2 and just needs to end with an even digit, e.g. 1998. However, today we are interested in all the digits being even. (Is 0 even? Yes, in as much as the series of even numbers begins 2, 4, 6, 8, ..., so 0 fits in if we extend the series backwards one place.)

The next one is fairly soon after 2/2/2000: 4/2/2000 and there are several more in February 2000. Can you tell me how many even dates there are in February 2000?

Can you tell me when the previous even date was that only had only even digits in it before February 2000? Hint: it was a very long time ago.

#### What an odd day!

Interestingly, it was not too long ago that there was a date composed solely of odd digits - an odd date. It was in November 1999. What dates in that month were odd dates?

When is the next odd date? Hint: it is a very long time in the future.

So within 4 months we have had both dates that are solely even and purely odd dates.

Will it ever happen again within one person's lifetime?