## Tuesday, July 3, 2012

### Speed! - Patterns in the Cards - Diagonals Part 2

This is the sixth 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 Four Speed the pattern was often a diagonal to the bottom left using several different decks as base decks.

The following base decks result in diagonals to the bottom left when combined with Four Speed.

Base Deck

Three Speed
Five Speed (not pictured - pictured last week)
Seven Speed

Nine Speed

(Do you see my mistake? One of the patterns is missing a Four Speed card.)

Diagonals Part 2
In many, but not all instances when Three 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 Three Speed and find the cards the two decks have in common (15 and 30). If the two decks were extended they would also conatin the common cards 45, 60, 75 and so on.
- Lay the common cards from Three Speed on top of the corresponding Five Speed cards.

The resulting pattern should look like this.

Which other bottom decks do you think will produce a diagonal when Three Speed is the top deck?

Bottom Deck
Two Speed
Four Speed
Five Speed
Six Speed
Seven Speed
Eight Speed
Nine Speed