## Tuesday, July 10, 2012

### Speed! - Patterns in the Cards - Diagonals Part 3

This is the seventh 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 Three Speed the pattern was often a diagonal to the bottom right using several different decks as base decks.

The following base decks result in a diagonal when combined with Four Speed.

Bottom Deck
Two Speed
Four Speed
Five Speed (not pictured - pictured last week)
Seven Speed
Eight Speed

Diagonals Part 2
In many, but not all instances when Six Speed is the top deck, the resulting pattern is a diagonal to the bottom right. Let's experiment with Five Speed as the bottom deck.

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

- Now get out Six Speed and find the cards the two decks have in common (30). If the two decks were extended they would also conatin the common cards 60, 90, 120 and so on.
- Lay the common cards from Six Speed on top of the corresponding Five Speed cards.

The resulting pattern should look like this.

A similar pattern is visible when Seven Speed is the base deck.

When Two Speed, Four Speed and Eight Speed are the base decks this diagonal is still visible, but these decks have additional common factors with Six Speed which results in the double diagonal pattern which can be seen as follows.

Next week will be the last week for this series of posts. We will find out what happens when Seven Speed, Eight Speed and Nine Speed are top decks.