Data Type Fundamentals

The Python programming language uses data types to distinguish between different types of information.

Dependencies

Students need to have these skills before learning this skill:

• Creating and Changing Variables

Goal

When you teach this skill, your goal is to make it so that students know the following:

• Every value has a data type.
• The int data type is used for storing whole numbers.
• The str data type is used for storing text.

Activities

Here are some activities that you can do in order to teach this skill.

Two different kinds of addition

1. Explain that every value in the Python programming language has a data type.

2. Write 100 on the board. Explain that 100 is an int. Explain that we store whole numbers in ints.

3. Write "Hello!" on the board. Explain that "Hello!" is a string. Explain that we store text in strings.

4. Ask students to come up with two examples of ints. For this example, let’s say that students came up with these two ints: 101 and 102.

5. Write an addition expression on the board that uses the two ints. In this example, you would write 101 + 102.

6. Ask the students what the result of that expression is going to be.

7. Now, ask students tog come up with two examples of strings. For this example, let’s say that students came up with these two strings: "hot" and "dog".

8. Write an addition expression on the board that uses the two strings. In this example, you would write "hot" + "dog".

9. Ask the students what the result of that expression is going to be.

10. Now, write this code on the board:

    p1_score = 7

11. Ask students to tell you what the data type for the p1_score variable is.

12. Add some more code to what you wrote on the board. At this point, the entire program that’s written on the board should look like this:

    p1_score = 7
    p2_score = 11

13. Ask students to tell you what the data type for the p2_score variable is.

14. Add some more code to what you wrote on the board. At this point, the entire program that’s written on the board should look like this:

    p1_score = 7
    p2_score = 11
    print("Total score:")
    print(p1_score + p2_score)

15. Ask students what they think the program is going to do, and then explain what it actually does.

16. Add some more code to what you wrote on the board. At this point, the entire program that’s written on the board should look like this:

    p1_score = 7
    p2_score = 11
    print("Total score:")
    print(p1_score + p2_score)
    
    p1_name = "Alice"
    p2_name = "Bob"
    print("Good work, " + p1_name + " and " + p2_name + "!")

17. Ask students what they think the program is going to do, and then explain what it actually does.

18. Add some more code to what you wrote on the board. At this point, the entire program that’s written on the board should look like this:

    p1_score = 7
    p2_score = 11
    print("Total score:")
    print(p1_score + p2_score)
    
    p1_name = "Alice"
    p2_name = "Bob"
    print("Good work, " + p1_name + " and " + p2_name + "!")
    
    print(p1_score + p1_name)

19. Ask students what they think the program is going to do, and then explain what it actually does.