How do I create a Formula question with a single variable?
You can create a quiz question that involves a formula with a single variable. Based on the variable and formula definitions, the question could change for every student.
Note: If you need help adding a mathematical formula in the Rich Content Editor, please see the Math Editor lesson.
Create a New Question
Edit Question Name and Point Value
Type a name in the name field  and the point value in the points field . Type the question prompt text and formula with variables in brackets in the Rich Content Editor . You can include video, images, math equations, or flash activities. Click the Need help? link  for more advanced options.
Note: If you need help adding a mathematical formula in the Rich Content Editor, please see the Math Editor lesson. You cannot use the letter "e" as a variable. It is a reserved mathematical constant.
Set Variable Definitions
After you have finished typing the formula in the Rich Content Editor, parameters to define the formula will appear. Set the variable definitions for the formula. Specify the minimum and maximum numbers for variable X . Setting a minimum will prevent a division by zero.
Select decimal places in the drop-down menu , and click the Recompute button  to verify that Canvas will insert a number into the formula that is within the variable definition.
Set Formula Definitions
Type the formula definition in the formula field . Make sure the formula does not contain any brackets or equal signs. Select the Decimal Places drop-down menu  to set the number of decimal places you want used for the result. Select the Save button to save your formula .
Once you've added a formula definition, you can go back to the Recompute button and watch the calculated variable process through the formula, creating the result. You can recompute as many times as you'd like. For instance, in this example, the number 30 acts for x and the result is -353.
Set Possible Number of Solutions
In the Offer field, specify the number of possible solutions you want Canvas to generate .
In the error margin of field, enter the margin of error for the student's answer . Responses are based on relative error in addition to absolute error. Margins of error can be created as a percentage or as a point value (up to three decimal places).
Click the Generate button to view final answer .
View Possible Solutions
Possible solutions will process according to the number of value combinations.
You can provide feedback for the question by clicking a feedback bubble and entering text. The bubbles are color-coded to correspond with the type of answer the student provides. Green is for correct answer feedback , red is for incorrect answer feedback , and blue is for general question feedback .
Click the Preview button  if you want to verify the quiz before you publish it. When you are ready, click the Publish button .
Student View for Formula Question
This is what students see when they encounter a Formula question in a quiz.
Student View for Formula Question Correct Answer
If you allow students to see the correct answers, they will see the correct responses listed after their answer.
Student View for Formula Question Incorrect Answer
If you allow students to see the correct answers, they will see the correct responses listed after their answer. If the student got the answer incorrect, a red flag will indicate the answer was incorrect.