Expressions with parentheses

The topic  is under the 5th Grade Math Mission. This exercise helps understand the use and importance of parentheses.

Types of Problems
There are four types of problems in this exercise:


 * 1) What is being done: This problem has a worked out arithmetic problem involving parentheses. The student is asked to select which of the situations is being modeled by the expression.Ewp1.png
 * 2) When parentheses matter: This problem has several arithmetic expressions written in a column on the left. The student is asked to select correctly whether the parentheses are important to the expression or if removing them would leave the value unchanged.Ewp2.png
 * 3) Write numerical expression: This problem describes a situation. The student is asked to write a numerical expression that models the situation being described.Ewp3.png
 * 4) Evaluate expression: This problem has a numerical expression which the student is asked to correctly evaluate.Ewp4.png

Strategies
This exercise is easy to get accuracy as most of the problems are really just based on order of operations. The speed badges are also easy because the tolerances are set generously because of one somewhat lengthy problem.


 * 1) On When parentheses matter the left column is that the expression is changed (they do matter) and the right is that the value is unchanged (they don't matter).
 * 2) On When parentheses matter the answer is generally that when parentheses are around multiplication they don't matter and when they are around addition they do.
 * 3) On When parentheses matter the notable exception to two above is that in $$a\times b+(c+d)$$ the parentheses don't matter.
 * 4) On Write numerical expression the problem evaluates whatever you write, so you can just write the actual numerical answer to the problem if you wish.