JSS 3 First Term

Lesson objectives

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

1. Define a function and state its input and output parameters.
2. Call a function by passing values correctly.
3. Declare a one-dimensional array and index elements properly.
4. Use an array to store multiple values in sequence.
5. Trace a function call returning a value correctly.

Key vocabulary

• Function: a reusable block performing one computation.
• Parameter: an input variable receiving a passed value.
• Return: giving a value back to the caller after computation.
• Array: a sequence stored in consecutive memory slots.
• Index: the position number of an element in the array.
• One-dimensional array: an array storing values along one axis.
• Reusable block: a section of code called multiple times with different inputs.
• Trace: predicting results by stepping through code.

Common misconceptions

• "Functions replace loops." Functions handle single operations; loops handle repetition.
• "An array stores text." Arrays store homogeneous values; text often sits in a string type separately.
• "Index starts at zero always." Zero-based indexing is common but some languages start elsewhere.

Teacher activities

1. Starter: ask why repeated tasks should use functions rather than duplication.
2. Define a function and give input and output parameters explicitly.
3. Demonstrate calling a function by passing values.
4. Declare a one-dimensional array and index elements step by step.
5. Demonstrate calling a function returning a computed value.
6. Close with the function-trace task and exit question.

Student activities

1. Answer the starter and state the benefit of reusing functions.
2. Define a function in their own words and name input and output parameters.
3. Call a function by passing the correct values.
4. Declare a one-dimensional array and index elements properly.
5. Trace a function call and write the returned value.
6. Answer the exit question comparing functions with loops in one sentence.

Practical / learning evidence

A declared array with indexing exercises, a function call with a returned value, and a function-trace worksheet. Submit all three for marking.

Resources and preparation

Computers with the interpreter, blank arrays 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 array declaration for correct indexing. Check the function return value matches the traced result. Mark the function trace for correct parameter passing. Flag any learner who thinks functions replace loops entirely.

Inclusion and homework

Provide the array template prefilled for learners who need scaffolding and allow oral function calls. Extend confident learners with two arrays and a function that returns an array element. Homework: write a second function that takes an array and returns the sum of its elements.