Flubaroo used to be the go-to recommendation for scoring a Google Form, but now you can create a quiz in Google Forms with correct and incorrect answers for questions with multiple choices, checkboxes, or drop-down options. Here's how to make the magic happen:

Create a new quiz

1. Go to forms.google.com.

2. In the template chooser, click the template box above "Blank quiz."

Change a form to a quiz

1. Go to forms.google.com.

2. Open a form or make a new one.

3. At the top right, click Settings .

4. Click QUIZZES.

5. Next to "Make this a quiz" click the switch .

6. Click SAVE.
   

Assign points to questions

You can make an answer key for multiple choice, checkbox, or drop-down questions.

1. To add a new question, click Add .
   
2. Fill out your question and answers.
   
3. In the bottom left, click ANSWER KEY.
   
4. In the top right of the question, choose how many points the question is worth.
   

Note: To go back and edit the question or options, in the bottom left, click EDIT QUESTION.

Add explanations to answers

You can add links, videos, or websites to answers to explain them further. Respondents will see your feedback only after they finish the quiz.

1. Click a question.
   
2. Click ANSWER KEY.
   
3. Click ADD ANSWER FEEDBACK.
   
4. Type feedback for "INCORRECT ANSWERS" and "CORRECT ANSWERS," then click SAVE.
   
   

See quiz responses

You can see automatic summaries of all the responses to a quiz, including:

• Frequently missed questions

• Graphs marked with correct answers

• Average, median, and range of scores

Sources:
https://support.google.com/docs/answer/7032287?p=quizzes&rd=1
https://goo.gl/RyS862