## Tuesday, June 19, 2012

### Speed! - Patterns in the Cards - More Checkerboards

This is the fourth post in an extension of the Speed! Patterns in the Cards posts. - I created the fun card game Speed! to teach multiplication. It uses skip counting to teach children to multiply and how to multiply faster. The series of Patterns in the Cards blog posts are meant to show some activities that can aid in number sense development using the Speed! cards.

Cool patterns become visible when two decks of Speed! cards are placed one on top of the other matching numbers. Last week we found that if the top deck was double the base deck the resulting pattern would look like a checkerboard.

If you tried the additional activities from last week you should have seen more checkerboards.

Base Deck       Top Deck
Four Speed        Eight Speed
Three Speed      Six Speed

Did you find another way to make a checkerboard? A checkerboard pattern is also produced when the top deck is Two Speed and the base deck is an odd number. For example; base deck = Five Speed, top deck = Two Speed.

First lay Five Speed, the base deck out like this.

- Now get out Two Speed and find the cards the two decks have in common (10 and 20). If Two Speed was extended it would also conatin the common cards 30, 40, 50, 60 and so on.
- Lay the common cards from Two Speed on top of the corresponding Five Speed cards.

If Five Speed is extended up to 200 and corresponding Two Speed cards are placed on top, your cards should look like this.

It's another checkerboard pattern!

Now try some more odd decks with Two Speed on top and see what happens.
Base Deck
Seven Speed
Nine Speed

There are still more ways to make a checkerboard pattern. Did you find them?