SS 2 Third Term

Lesson objectives

By the end of the week, learners should be able to:

1. Define a variable and name at least four data types.
2. Assign values to variables and display them correctly.
3. Convert between string, integer and float types.
4. Store a list of values in a single variable.
5. Trace a simple variable declaration and assignment.

Key vocabulary

• Variable: a named container holding a value.
• Data type: the category defining what values a variable holds.
• Integer: a whole number without fractional parts.
• Float: a number with fractional parts.
• String: text held as an immutable sequence.
• Boolean: a true or false value.
• List: an ordered collection stored in consecutive slots.
• Declaration: stating the size and type of a variable explicitly.
• Assignment: giving a value to a previously declared variable.
• Display: showing a value on screen via print().

Common misconceptions

• "Variables hold text automatically." Text sits in a string type explicitly declared.
• "Every variable holds one value only." Python lists hold multiple values.
• "Assignment copies the value forever." Assignment binds the name to the value; reassignment later changes it.

Teacher activities

1. Starter: display a printed word and a printed number and ask which need explicit typing.
2. Define a variable and state why Python uses explicit typing.
3. Name four data types one by one and assign example values.
4. Demonstrate assigning an integer, a float and a string.
5. Show declaring a list of values.
6. Close with the declaration task and exit question.

Student activities

1. Answer the starter and state why variables need explicit typing.
2. Define a variable in their own words and name four data types.
3. Assign an integer, a float and a string with sample values.
4. Display each assigned value with print() in separate statements.
5. Declare a list of five values and index the first and last.
6. Answer the exit question in one sentence about Python types.

Practical / learning evidence

A declared variable worksheet with type checks, a runnable arithmetic program and a list demonstration. Submit all three for marking.

Resources and preparation

Computers with a Python interpreter installed, blank variables and sample tracing cards. Prebuild the interpreter in a read-only folder. Disable Caps Lock before typing. Verify the computer starts reliably.

Assessment for learning

Inspect the declared variables for correct names and matching types. Mark the runnable program for sensible arithmetic. Check the list demonstration for correct indexing. Flag any learner who assumes variables carry text automatically.

Inclusion and homework

Provide the variable template predeclared for names and allow oral type assignment. Allow extra time on the runnable program. Extend confident learners with three more data types and a seventh homework displaying one boolean variable. Homework: write a second program declaring two variables of different types and combining them with arithmetic.