# Newsletter #2 : Happy Easter

[This is a back-issue of this website’s newsletter]

Happy Easter!

This year, Easter Sunday falls on the 23rd of March. Amazingly, this is almost the earliest it can possibly be. It’s certainly the earliest any of us will see – it won’t fall on March 23 again until the year 2160.

Easter Sunday can be earlier than March 23, though. The earliest possible date for Easter Sunday is the 22nd of March. The last time this happened was in 1818. The next time it happens will be 2285. Don’t hold your breath!

Even more amazingly, the date of Easter Sunday can actually be calculated with a mathematical formula simple enough for kids to understand. I used a formula invented by Carl Friedrich Gauss, who lived from 1777 to 1855 (so was alive on Easter Sunday, 1818). His formula can be understood by anyone who understands division with remainders, although the explanation given on wikipedia is a little brief. Who knows, perhaps I’ll write up an Easter Math Formula page one day, and suggest some games and activities for kids to play with Easter Sunday calculations…

Be sure that when I do, you’ll hear about it through this newsletter.

The real occasion for this edition is a teaching tool I call foldable number sheets. These are a useful tool for helping kids understand how our number system works – what do the digits in a multi-digit number mean? Why do we have a ‘0’ in “three hundred and five”? Why is “ten hundred and twelve” the same as “one thousand and twelve”?

I learned about this tool from my son’s grade 2 math book. I thought it was a great idea, and used it to help him understand some point that was troubling him. (I took a video of this, by the way, which you can see on my website.)

Since I’d already made up some foldable number sheets for him, I decided to give them to the world too, on Dr Mike’s Math Games for Kids. You can download and print for yourself as many foldable number sheets as you like. There are various sizes, suitable for one-on-one teaching, or for classroom demonstration. I hope they’ll be useful to you, especially if you are working with younger kids!

Anyway, that’s about all for this email.

Yours,
Michael Hartley

PS – If you received the first email, and are wondering what happened to Fish+1 and Spirographs…. They’ll be ready soon! Don’t worry!