15-minute session: read for 3 minutes, trace for 3, experiment for 7, and complete the check for 2. Spend longer whenever you need.
A decision chooses which statements run. The policy here is “ready at 80 or higher.” Trace 85, 79, 80, and 81 before running each case. The comparison includes 80. A program that prints the right answer for 85 may still be wrong at the boundary. Add a separate check rejecting scores below 0 or above 100; rejection and needing practice mean different things.
Line numbers describe program order. GOSUB visits a subroutine and RETURN resumes the caller. SYSTEM exits this interpreter. BASIC dialects differ: a 6502 or Z80 computer does not automatically run this exact dialect.
10 LET S = 85
20 IF S >= 80 THEN PRINT "Ready"
30 IF S < 80 THEN PRINT "Practice"
40 SYSTEM
Expected result: Ready
Keep three notes: your prediction, the actual result, and why they match or differ. The completion check grades understanding; the practice task builds skill.