Count : To count means to find out the number of objects by adding one for every object.

Coordinate : A coordinate is a number that describes the location of a point in space with respect to a direction.

Map : In mathematics mapping means assigning exactly one value to an object. A function maps every $x$ to exactly one $y.$

Negative : A number is negative if it is $\lt 0.$

Point : A point is an element in a space. Shapes are made of sets of points.

Reflection : A reflection is a transformation that mirrors a shape at a line. Reflections turn shapes into congruent shapes.

X-axis : The horizontal axis in a two-dimensional coordinate system.

Y-axis : The vertical axis in a two-dimensional coordinate system.

Equation : An equation is a mathematical statement in which two expressions are written with an equal sign in between. A solution of an equation is a set of variables that makes the statement a true statement.

Squared : $x$ squared refers to the number $x^2=x\cdot x.$ For example 3 squared equals 9.