Expression value intuition

The  exercise appears under the 6th grade (U.S.) Math Mission. This exercise analyzes the effect of certain changes on the value of variables in expressions.

Types of Problems
There is one type of problem in this exercise:


 * 1) Determine the effect of the change: This problem provides an expression and describes a potential change on the variable. The student is asked to determine how the proposed change in the variable would effect the result of the expression.Evi1.png

Strategies
Knowledge of the substitution property and variation are encouraged to ensure success on this exercise.
 * 1) These problems can be performed by plugging in some beginning number (like zero or one) then performing the change and re-evaluating the expression.
 * 2) In general, for linear expression (of the form mx+b) if m is positive, increase is associated with increase and decrease is associated with decrease.
 * 3) In general, for inverse variation (of the form A/x) increase is associated with decrease and decrease is associate with increase.

Real-life Applications

 * 1) Some of the problems in this exercise can be viewed as a beginning-level understanding of slope, which is important all the way up to and including the calculus.
 * 2) Some of the problems in this exercise are connected with the concepts of direact and inverse variation.