The hook
Quantitative reasoning = does this number make sense? Sanity-checking, blunder detection, independent estimation. The fastest surveyors aren\'t the ones who never make mistakes; they\'re the ones who catch their mistakes before delivery.
Memorize these
Concepts that show up on the exam
Order-of-magnitude check
Before computing precisely, estimate to 1-2 sig figs. A field crew expecting a 5-acre parcel that comes back as 0.5 ac or 50 ac knows something's wrong before computing further.
Independent verification
Compute the same answer a different way. Areas: shoelace + DMD should agree. Distances: GPS + total station should agree within budget.
Blunder detection
A blunder is gross — typically 10x or more the random-error budget. Statistical tests (3σ rule, redundancy in least squares) catch them automatically.
Reasonableness checks
Compare results to expectation. A new parcel with 10x the area of the deed call needs explanation. An RTK shot with 5 cm vertical residual on a known point needs explanation.
Data quality flags
Annotate uncertainty in your deliverables. "Coordinates approximate" or "Boundary in question — see survey note 3" beats silently shipping bad data.
Test yourself
How well did it stick?
A quick 5-question check on Quantitative Reasoning. See where you stand and what to review.