SYSE.50:5.1 - Build a useful human assistance rule

A person regularly totals stock lots. Prior comparable work supports mental decomposition of 347 × 6, but some occasions require keeping other intermediate values or retaining written working. The constructor compares complete mental, paper and calculator ways: entry, setup, arithmetic, checking and reporting all count. In the constructed evidence, a ready calculator frees working attention when those other values must be held; the mental way is adequate and cheaper when no such benefit or written record is needed.

Build a short rule from observable conditions. If the current quantity per lot is missing, obtain it from the relevant source or return the gap. If the expression is complete and the person has the supported mental way with no added record/burden need, use it and report the computed total: 2082 for this case. If a recoverable digit record is required, use the adequate written layout. If an already available, checkable calculator protects the other task values at worthwhile whole cost, enter and inspect 347 × 6, use its 2082 return and stop. This is an explicit engineering rule for the supplied conditions, not a statistically calibrated confidence threshold.

Test the rule on fresh comparable tasks, including an already sufficient case, a genuinely missing quantity and an aid whose display cannot support the required input check. Compare missed support and needless setup as well as correct totals. A high confidence report cannot replace the missing quantity, and adequate unaided ability does not negate the calculator’s possible benefit. Return a mistyped expression to SYSE.42 and a lost carry row to SYSE.52 before changing this assistance rule.

If the target instead is learning to use a carry, HCD’s practice design can select a hint that lets the person perform the addition. Giving 2082 can finish the numeric task while removing that practice contribution. The rule and its evidence must follow the declared target; supported success alone supplies no unaided-learning conclusion.