# Define Number Systems

##### This Define Number Systems video also includes:

Too many times learners just memorize the rules and patterns of complex numbers without really understanding where they came from. This short and clear video does a great job of giving reasoning for the development of the complex number system, without falling into intimidating jargon or notation. It provides a thorough review of the different number systems up to the real numbers, with particularly careful treatment of rational and irrational numbers. In addition, the emphasis on consistent operations leads directly to an upper-level treatment of closed systems.

CCSS: Designed

##### Instructional Ideas

• Play a modified game of pin-the-tail-on-the-donkey by drawing the Venn diagram from the video on the board and having learners pin numbers into the appropriate place
• Viewing the video gives great motivation to an introductory lesson or discovery learning activity on the imaginary numbers
• Consider playing as a broad refresher at the end of the year when doing end-of-course exam review
##### Classroom Considerations

• Video play requires updated Adobe Flash player and Internet access
• Creation of free LearnZillion account required to access lesson material
• Note that this video motivates the complex number system, but does not mention it. Rather, it points out plainly that that there is no number that, when squared, gives a negative result
• Lesson slides for notes are available under the Additional Materials tab
##### Pros

• Clear and easily understood narration
• Diagrams proceed logically and include previous information
• Careful and accurate treatment of different categories without jargon
##### Cons

• No blank Venn diagrams made available
• Lesson leaves the learner hanging with the question of what square gives a negative, with no answer
• No workable problems or guided practice provided