Quandaries
and Queries 

Name: crystal Question: 

Hi Crystal, I expec that by "a rule with a variable" your child's teacher is looking for a mathematical expression with an unknown in it. For example the area of a rectangle is the length by the width, and for a square the area is the length times the length. For a rectangle you might write this
and for a square
The first expression has two variables, length and width, and the second has one variable. For a circle the area is given by
This again is a rule with one variable, the radius. The radius is a variable because it depends on the size of the circle but pi is not a variable. Its value is always the same, pi = 3.1416... Penny 

