Testing and debugging programs
Test visual programs by predicting what should happen, running them, finding where the behaviour differs (bugs) and fixing them one change at a time
Lesson
Set out your lesson
“Testing and debugging programs means predict what should happen, run it, find where behaviour differs (a bug), and fix one change at a time. We will run a paper arrow program, spot a bug, fix one step, then check a fresh short program.”
Bring to the table
- Paper “program” of 4 arrow steps for a toy/robot walk across the table
- A small toy as the runner
- Optional later: adult-previewed CS Unplugged companion
Extra for the adult
Worked example. If arrows say right when they should say left, the toy misses the cup. Change one arrow, then test again.
Optional challenge. For Testing and debugging programs, plant two bugs and insist on fixing one change at a time.
What to notice. Keep one parent note: prediction; bug found; single-step fix; support used. This session samples testing habits, not mastery of coding.
Share and support
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Teaching approaches
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1 approach
Testing and debugging programs means predict what should happen, run it, find where behaviour differs (a bug), and fix one change at a time. We will run a paper arrow program, spot a bug, fix one step, then check a fresh short program.
Spend about 13 minutes predicting, running, and fixing a table “program” one change at a time, then checking a new sequence.
Family records and proof options
Keep a record of your learning
Save photos, notes, and attendance. Export a proof packet for compliance or portfolio reviews.
Practice this concept
Start practiceTesting and debugging practice
Predict, run, find the bug, and fix one change at a time.
Free · no login · no ads · Practice answers and completion are not saved. Parent observation remains the lesson record.
Learning resources
Extra practice links — they do not replace Gakuva’s teaching approach.
CS Unplugged · Practice link — not the full lesson
Computer Sciencewithout a computer
Before you open · source notes
Free computing activity hub useful for Testing and debugging programs. An adult picks one activity; not a single graded exam.
Free activity pages, no sign-in required for the tested path.
Before you openAsk the learner what steps they followed and what they would try next.
Opening this link does not save learning or assess mastery.
Source, access and review notes
Public CS Unplugged page. An anonymous GET on 2026-11-12 returned HTTP 200 with no login or payment prompt for this URL. Opening the link does not save practice or assess mastery. An adult should preview and guide the learner.
CS Unplugged. “Computer Sciencewithout a computer.” External page; Gakuva does not copy, host, embed, or redistribute materials.
Unknown — link only
Check understanding
- Predict what a short program should do for given inputs, including unusual ones (e.g. a wrong or blank answer), run it and record whether each result matched
- Find and fix a bug in a given program (e.g. a character that turns the wrong way or a loop that repeats too many times)
- Explain how they tracked down the bug (e.g. running one part at a time, checking each block against the algorithm)
“When your child's coding project doesn't work the way they wanted, do they test it, hunt for the 'bug' and fix it step by step rather than starting over?”
Curriculum record
- Type
- Procedural
- Subject
- Computing
- Domain
- Algorithms & Programming
- Age range
- Ages 6–13
Standards