Lesson 1: Mastery Check Solutions
It’s time to put your detective skills to the test! By now you are a master number detective that has classified a variety of numbers based on their mathematical characteristics. For this activity, you will be the teacher and determine if a student has also mastered these skills.
Show What You Know
- Mr. Lamotte is grading his class’ math tests. One of the questions from the test is in the box below.
Plot each of the numbers below on a number line. Record the rational numbers in blue and the irrational numbers in red.
Teachers always need an answer key. In the space below, answer Mr. Lamotte’s test question to create an answer key.
Note
Responses may vary but should resemble the modeled solution below.

- As the teacher, you need to evaluate each student’s answer and provide feedback that the student can learn from. Look over the student’s response below and compare it to the solution you created as your answer key.
Student’s Response:

Complete the rubric below after carefully comparing the student’s solution to your answer key.
Indicate the points you feel the student deserves and provide feedback. Be sure to praise the student for what they did well, and make suggestions for improvements to help increase their understanding.
Grading Rubric
Criteria | 1 Point | 0 Points | Points Students Earned | Feedback for the Students |
The number range on the number line is accurate for the data. | The number line created has a range that accurately includes all of the data. The lowest value should be less than the lowest number in the data set, and the highest number should be greater than the highest value in the data set. | The number line does not display an accurate range. | ||
5.681032752401… Red = irrational |
The number is correctly color-coded. | The number is not correctly color-coded. | ||
5.3
is correctly color coded as rational or irrational. Red = irrational |
The number is correctly color-coded. | The number is not correctly color-coded. | ||
Red = irrational |
The number is correctly color-coded. | The number is not correctly color-coded. | ||
5.681032752401… is correctly placed on the number line. |
The number is correctly placed. | The number is not correctly placed. | ||
5.3 is correctly placed on the number line. |
The number is correctly placed. | The number is not correctly placed. | ||
|
The number is correctly placed. | The number is not correctly placed. | ||
Total Points |
Final Grade: |
- In the space below summarize the difference between rational and irrational numbers. Be sure to include the categories rational numbers can be classified into. This information will help the student be successful on future assignments.
Note
Answers may vary but should include the key points listed below.
Rational numbers include positive and negative whole numbers, terminating decimals, and repeating decimals. Rational numbers can be classified into the categories of whole numbers, integers, and natural numbers. Irrational numbers are decimals that do not repeat or terminate, and numbers that can not be written as a fraction or whole number.
Say What You Know
Talk to a peer or instructor about what you have learned in this lesson and how you used these skills to complete this activity.