Are sequences functions? Why can’t the popular “vertical line test” be applied in some cases to determine if a relation is a function? How does the idea o

Focuses on essential knowledge for teachers about proof and the process of proving. It is organised around five big ideas, supported by multiple smaller, interc

Do your students think that the vertical line test is indispensable and foolproof for determining whether a relationship is a function? Do they believe that eve

"A series for teaching mathematics."--P. [1] of cover.

How does working with data in statistics differ from working with numbers in mathematics? What is variability, and how can we describe and measure it? How can w