Two hands-on lessons · No account, screen, or coding required
Make the invisible something you can see.
Start with paper. Carry the same thinking into the Computer Adventures. Read aloud, draw, or explain with your hands—there is more than one way to show understanding.
Can your partner follow your plan without guessing?
Learning goal
Give a precise sequence, follow it, and fix one unclear instruction.
Before you start
No coding knowledge. A learner can point to a shape or direct a partner with support.
Why it matters
A program is a plan expressed as instructions. Computers need instructions they can interpret; they do not infer what we meant.
Gather
Paper, a pencil, and three large paper shapes: a circle, a square, and a triangle.
Predict
Draw a row of three empty boxes. Agree that the leftmost is box 1. Say: “Put the circle in box 1, the square in box 2, and the triangle in box 3.” Point to where you expect each shape to end up.
Try the plan
One person gives one instruction at a time. The other follows it exactly. Pause if a word is unclear; agree on its meaning together. Swap jobs.
Find the ambiguity
Give this instruction: “Put the triangle next to the circle.” Could that mean more than one place? Replace it with “Put the triangle in box 2.” Notice how a clear location removes the guess.
Change the order
Use one circle only. First put it in box 1, then move it to box 3. Predict the final box. Reset and reverse those two instructions. Explain why the circle now ends in box 1.
Show what you learned
Make a fresh two-instruction plan for the square. Your partner must predict its final box before following it. Explain which instruction decides where it finishes.
Facilitator notes, answer, and a stretch
Look for a precise box number and an explanation that the later instruction changes the earlier placement. If the learner guesses, point to the circle after each instruction. A correct final box without a trace is a reason to practice again.
Stretch: find two instructions whose order does not change the result, such as placing two different shapes in different empty boxes. Explain why order matters sometimes, rather than always.
Make it fit: Explorers point while an adult reads; Discoverers give the directions aloud; Strategists write and swap plans; Thinkers define a tiny instruction vocabulary and test an ambiguous command.
Ready for the adventure? The learner can follow a new two-step plan and explain the final position. Then try numbers in You’re the computer →
Record state after each instruction and locate the first mismatch between a prediction and a trace.
Before you start
Follow ordered instructions, add small numbers, and explain that reading a stored value does not empty it. If unsure, complete Adventure 2.
Why it matters
Debugging means using evidence to find where a program differs from its intended behavior. A trace makes that evidence visible.
Gather
Paper with columns Step, A, B, and Total. This paper model is not LearnRisc or a claimed assembly instruction set.
Predict before you trace
Start A, B, and Total at zero. The plan is: set A to 3; set B to 2; set Total to A + B; set B to 4. Predict all three final values.
Record each change
Make one row after each instruction. Copy values that do not change. Does changing B at the end automatically update Total?
Find and repair the bug
The goal was to add 3 and 4. Find the first instruction that calculates too soon. Move “set B to 4” before the addition, then trace from zero again. Explain why the repaired Total is 7.
Test a fresh case
Change A’s starting value to 5. Predict the original program’s Total and the repaired program’s Total. Trace both. Which result supports your explanation?
Reveal the trace and facilitator notes
Original program, after each step
Step
A
B
Total
Start
0
0
0
Set A to 3
3
0
0
Set B to 2
3
2
0
Total = A + B
3
2
5
Set B to 4
3
4
5
Total stays 5 because no later instruction writes it. With A = 5, the original Total is 7; the repaired Total is 9. Ask the learner to explain the write, not memorize the answer.
Advanced stretch: a loop that lies
After Adventure 3, trace this paper plan: set Left to 3 and Done to 0; add 1 to Done; subtract 1 from Left; repeat those last two actions while Left is not zero. It ends at Left = 0 and Done = 3. Now replace “subtract 1” with “subtract 0.” Stop your paper trace after five passes. Explain why a safety limit is different from a correct stopping rule.
Stretch answer and boundary case
Left remains 3 and Done keeps growing, so the condition never becomes false. Restoring the subtraction makes progress toward zero. Starting this do-then-check loop at zero would still do the body once and then go negative: add a check before the body if zero repetitions should do nothing. No need to run indefinitely to prove the bug.
Make it fit: Explorers use large paper number cards with an adult and one changing value first; Discoverers speak each row aloud; Strategists compare original and repaired traces; Thinkers add the zero-count boundary case and justify the stop check.
Evidence of understanding: explain why Total does not update itself, find the first wrong step, and predict both fresh-case results. Need practice? Revisit stored values. Ready to extend? Try loops or its stretch, then read the planned LearnRisc direction.