Breaking problems into functions
Design a program as small functions you can test one at a time.
Planned. This module is part of the plan and is not written yet.
Why it matters
Planning a school sports day breaks into small jobs: register runners, time races, announce winners. Big programs are built the same way, one small tested function at a time.
Draft outline · in review- For
- Level 9–12 · JSS 3 (BECE) to SSS 3 (WASSCE)
- Inside
- 5 lessons and a test · about 90 minutes
- Topic
- Python functions · extension, 3 of 4
Inside the module.
5 lessons in order, about 90 minutes in all, then a short test. Learners go at their own pace; the minutes are a guide, not a timetable.
Draft outline · in review
Lesson 1: Decomposition
Split a problem into jobs small enough to name in a few words.
Explain15 min, from minute 0
Lesson 2: A mark sheet in pieces
Design a mark-sheet program as read, average and report functions.
Worked example20 min, from minute 15
Lesson 3: Test each piece
Check each function on its own with small examples and assert.
Practice20 min, from minute 35
Lesson 4: Build and join
Build a small program from tested functions, then join them.
Project30 min, from minute 55
Lesson 5: Check your skills
Choose good splits for new problems.
Review5 min, from minute 85
End-of-module test
Break a new problem into small functions, test each one alone and join them into a working program.
Mastered at 85% or more. Retake it until you pass; nothing is lost, and each try gives feedback.
Already know it? A Challenge Test (planned) clears the whole module: 90% overall, no objective below 75%.
Last stageafter about 90 min
Practicalities
Draft outline · in reviewBuilt to run offline
Planned to run on the Lantern's own computer, with no internet needed.
Languages
Planned first in English; every module aims to reach all of the Lantern's languages.
Try a question.
One question from the module, as a learner would meet it. Have a go, then open the worked solution a step at a time.
Draft outline · in review
A program must read learners' scores, work out the average and print who scored above it. Which design is best?
Particulars
Where it sits
What a learner can do after it
- Decompose a problem into small functions.
- Test each function on its own before joining them.
Level
Level 9–12 · JSS 3 (BECE) to SSS 3 (WASSCE)
Level mappings are approximate. A qualified teacher or lecturer in each country must check them before they appear in the app.
Difficulty for its level
3 of 4 · Extension
Time
About 90 minutes
Alignments
None drafted yet.
Alignment in review until a qualified teacher or lecturer checks it. No exam body, university or vendor endorses us; learners still sit the real exam.
Challenge Test
Planned: a Challenge Test to prove you know it and skip it. Pass at 90% overall, with no objective below 75%.
University courses it previews
Computer Science, Software Engineering
On these pathways
The route here.
Everything this module builds on, drawn as a route from its foundations. Solid lanes must be mastered first, or cleared by a Challenge Test; dashed lanes are suggestions that never lock anything.
- CO-BLK-SEQ-01 Instructions in order, Level 1–4, Coding. Planned.
- CO-BLK-SEQ-01Instructions in orderCoding · Primary 1 to Primary 4 (Level 1–4) · Planned
- CO-BLK-LOP-01 Repeat blocks, Level 3–5, Coding. Sample lesson in the demo.
- CO-BLK-LOP-01Repeat blocksCoding · Primary 3 to Primary 5 (Level 3–5) · Sample lesson in the demo Needs Instructions in order (required).Try the sample lesson: Repeat blocks
- DS-CMP-TYP-01 The home row, Level 3–6, Digital skills. Planned.
- DS-CMP-TYP-01The home rowDigital skills · Primary 3 to Primary 6 (Level 3–6) · Planned · recommended
- CO-BLK-CND-01 If this, then that, Level 3–6, Coding. Planned.
- CO-BLK-CND-01If this, then thatCoding · Primary 3 to Primary 6 (Level 3–6) · Planned · recommended
- CO-BLK-LOP-02 Patterns with loops, Level 4–6, Coding. Planned.
- CO-BLK-LOP-02Patterns with loopsCoding · Primary 4 to Primary 6 (Level 4–6) · Planned Needs Repeat blocks (required).
- MA-ARI-ORD-01 Order of operations, Level 5–6, Maths. Planned.
- MA-ARI-ORD-01Order of operationsMaths · Primary 5 to Primary 6 (Level 5–6) · Planned · recommended
- CO-BLK-LOP-03 Loops inside loops, Level 5–7, Coding. Planned.
- CO-BLK-LOP-03Loops inside loopsCoding · Primary 5 to JSS 1 (Level 5–7) · Planned · recommended
- CO-PRG-PYB-01Your first Python programCoding · JSS 1 to JSS 3 (BECE) (Level 7–9) · Planned Needs Patterns with loops (required), The home row (recommended).
- CO-PRG-PYB-02VariablesCoding · JSS 1 to JSS 3 (BECE) (Level 7–9) · Sample lesson in the demo Needs Your first Python program (required).Try the sample lesson: Variables
- CO-PRG-PYB-03Numbers and calculationsCoding · JSS 1 to JSS 3 (BECE) (Level 7–9) · Planned Needs Variables (required), Order of operations (recommended).
- MA-ALG-FRM-01Substituting into formulaeMaths · JSS 1 to JSS 2 (Level 7–8) · Planned · recommended
- CO-PRG-PYB-05Decisions with ifCoding · JSS 2 to SSS 1 (Level 8–10) · Planned Needs Numbers and calculations (required), If this, then that (recommended).
- CO-PRG-PYB-06Loops in PythonCoding · JSS 2 to SSS 1 (Level 8–10) · Planned Needs Decisions with if (required), Loops inside loops (recommended).
- CO-PRG-PYF-01Defining functionsCoding · JSS 2 to SSS 2 (Level 8–11) · Planned Needs Loops in Python (required).
- CO-PRG-PYF-02Parameters and return valuesCoding · JSS 3 (BECE) to SSS 2 (Level 9–11) · Planned Needs Defining functions (required), Substituting into formulae (recommended).
- CO-PRG-PYF-04Breaking problems into functionsCoding · JSS 3 (BECE) to SSS 3 (WASSCE) (Level 9–12) · Planned · the destination Needs Parameters and return values (required), Lists (required).
Help light the room where this is learned.
Every route on this map starts in a classroom with 24 stations, a tutor that works offline and a facilitator upstairs. Four are planned and waiting for light.