Why is 2 important?  It’s the only even prime number! What’s so special about 1323?  It’s an Achilles number! What about 1975?  Well it’s the year I was born! Spend some time learning about special numbers in this math mini spark.

Spark your math thinking!

1. Set up your math mini spark recording page: #37: What’s so special about that number?

2. Explore this article and find out about 4 types of special numbers. Write the name of each type and some examples on your recording page.

3. Look over this example.

Answer these questions

• How many of the numbers from 1 to 30 can you express as the difference of two perfect squares?
• What is special about the difference between squares of consecutive numbers? Why?
• What about the difference between the squares of two numbers which differ by 2? By 3? By 4…?
• When is the difference between two square numbers odd?
  And when is it even?
• What do you notice about the numbers you CANNOT express as the difference of two perfect squares?
• Reminder for your teacher-The answers to these questions can be found in the math mini park folder.

4.  Set your time for 8 minutes and explore the Almanac of Interesting Numbers at Mathigon.  In what ways could teachers and students use this site? What ways is it useful? What suggestions do you have? Record your responses on your recording sheet.

5. Share your math mini spark recording page with your teacher/EY coordinator.