The Canvas Publisher has a tutorial for a one variable formula quiz question here in their helpful online tutorial area.
Formula quiz questions might be useful in any course where simple calculations are to be tested.
Here is how you might write a two variable formula quiz question
Click on the Question Tab at the top and New Question at the bottom of the page. Select Formula Question as the question type from the drop down menu.
You can enter the point value to the right if not the default.
The next step is to write the question including the variables. These variable will be selected randomly from a selected collection (see below)
Here we have two variables, Cp0 and Vd. Notice that they are surrounded by . Canvas uses this notation to declare the variables.
Once the variables are declared in the question area they appear in the Variable Definition section. You can set the minimum and maximum values and the number of decimal places for each variable. Using the Recompute button you can get an idea of the possible values.
Moving to the Formula Definition section allows you to enter the formula for the numeric answer. Here we are calculating the dose required as Cp0 times Vd. These names need to match the names within the  in the question field. Various functions can be included, for example ln, abs.
Don't forget to click the Save button. This will verify your formula and provide a numeric result.
It may take you a few tries to get it right so you can delete bad formula attempts by clicking the red cross on the right.
Now you will need to determine how many version of this 'random' question to generate. With 160 in a class you might generate somewhere between 80 and 160?
You specify a tolerance that you will accept as correct.
Generate the number of possible solution by pressing the Generate button. This will take a little time depending on how many you choose to generate,
You can enter positive feedback in the green text text field (it will expand when you click on it) or helpful hints in the red wrong answer text field.
Finally don't forget to update/save the question or you will need to do it all again. If you notice a mistake or want to change something you can always edit the question and update/save again.