ABSTRACT
This chapter discusses common mistakes in math instruction and explains the misunderstandings behind them. On different occasions, Jane uses some mathematical terms or formulations not quite the way they are meant to be used. A term describing a mathematical concept usually has specific denotations and may not be easily exchangeable with another term. The problematic words or phrases are underlined, with a corresponding formulation or words to use suggested, presented in italics. Commas aren't part of a number. They're used simply for easier recognition. Although the diameter is indeed twice as long as the radius of a circle, defining it as two radii put together may lead to mistaking the two line segments for the diameter of the circle. An equation is a statement of equality of expressions. Figures or shapes drawn on a flat surface are often called 2-D geometric shapes. Geometric shapes that take up physical space are referred to as 3-D geometric shapes or solids.
