Grid-in (SPR) Protocol

On grid-ins there are no answer choices to sanity-check you and no partial credit — so the entry format is itself a question you must get right. About 25% of Math (~11 questions) is student-produced response: you type the answer, no multiple choice. Strong students lose these not on the maths but on the format — a mixed number, an over-rounded decimal, a missing minus sign.

Sources: official Bluebook test directions (verbatim rules below). Point convention: each = 1 of ~44 Math; Module-1 misses are ceiling-risk.

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#THE OFFICIAL ENTRY RULES (current digital SAT — NOT the old paper grid)

• Negatives ARE allowed. Up to 5 characters for a POSITIVE answer; up to 6 (incl. the minus sign) for a NEGATIVE answer.
• If a FRACTION doesn't fit the field → enter the DECIMAL equivalent.
• If a DECIMAL doesn't fit → truncate OR round at the FOURTH digit (enter as many digits as fit; don't over-round).
   e.g. 2/3 → enter 2/3, or .6666, or .6667  (a leading 0 is unnecessary and wastes a character)
• MIXED NUMBERS are NOT accepted → enter 3½ as 7/2 or 3.5 (the engine reads "3 1/2" as 31/2).
• Do NOT enter %, $, commas, or units. Convert π to a decimal (3π → 9.42).
• Fractions need NOT be simplified — any equivalent fraction that fits is fine.
• If a question has MORE THAN ONE correct answer, enter only ONE.

Why these exist (mechanism): the engine matches your typed string against accepted forms within a tolerance. A mixed number, a symbol, or an over-rounded repeating decimal falls outside the accepted set — marked wrong despite correct maths. Each format slip = a full question lost with zero warning.

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#THE PRE-SUBMIT CHECKLIST (run on every grid-in)

☐ Did I answer the EXACT quantity asked? (x, not x+1)
☐ Negative? minus sign typed.
☐ Fraction that fits? enter the fraction (safest — no rounding risk). Doesn't fit? decimal.
☐ Repeating decimal? give ≥4 digits (.6666 / .6667), never .66.
☐ No mixed number, %, $, comma, unit, or π symbol.
☐ Re-enter the value into Desmos / plug back in to confirm.

#TRAP TAXONOMY

• Mixed number typed ("3 1/2") → misread.
• Over-rounded decimal (.66 for 2/3) → outside tolerance.
• Missing minus sign on a negative answer.
• Symbol/unit entered (%, $, cm).
• Answered the wrong quantity (no choices to catch it).

#SAME ITEM, TWO LEVELS (MERIDIAN-original)

Answer obtained: the value is 7/2.

• ~700 (trap): types "3 1/2". Trap: mixed number → engine reads 31/2 → wrong, full question lost. [−1]
• 800 (precise): types 7/2 (or 3.5). Move: knew mixed numbers are rejected; chose the exact fraction (no rounding risk), then re-checked the ask.

#DIAGNOSE YOUR ANSWER

• Right maths, marked wrong on a grid-in? Format slip. Fix: run the checklist; prefer the exact fraction.
• Negative lost? Minus sign omitted. Fix: type it; remember 6-char budget.
• Repeating decimal wrong? Over-rounded. Fix: ≥4 digits.
• Answered wrong quantity? No choices to catch it. Fix: annotate the ask before solving.

#DRILLS (timed · self-marked · MERIDIAN-original)

Drill 1 — Format conversion (target 10/10, ≤3 min): convert to a valid grid-in entry: 3¼ · −2/5 · 2/3 · 150% · $4.20 · 9π · 1¾ · −0.333… · 12,000 · 5/10. Answers: 13/4 (or 3.25) · −2/5 (or −.4) · 2/3 (or .6666/.6667) · 1.5 (or 3/2) · 4.2 · 28.27 (enter as many digits as fit) · 7/4 (or 1.75) · −.3333 (≥4 digits) · 12000 · 1/2 (or .5). PASS: 10/10 in an accepted form. Drill 2 — Checklist habit: on your next 10 practice grid-ins, run the checklist aloud. PASS: zero format errors across the set. Repetition: any slip → redo the conversion drill next day.

#TRANSFER

Abstract rule: solve → choose the cleanest accepted format (fraction safest) → confirm the ask → re-verify. Topic-independent. Constant: the rules + checklist. Changes: the number.

#REFERENCE CARD — GRID-IN

Negatives OK (6 chars incl. −; positives 5). No mixed numbers (7/2 not 3 1/2).
Fraction that fits = safest. Repeating decimal → ≥4 digits (.6666). No % $ , unit π-symbol.
ALWAYS: answer the exact ask · re-enter to verify. No partial credit, no choices to catch you.
Each item = 1 of 44 Math Q; Module-1 miss = ceiling risk.

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MERIDIAN · FORGE · GRID-IN (SPR) PROTOCOL | v1.0