# Answer check and signed bridge

Read after your first attempt. A contains 10 rows and 10 distinct references. B contains 11 rows and 10 distinct references. The union contains 11 references. A totals 1,050.74 FC; B totals 1,272.74 FC. Raw B minus A is +222.00 FC.

Seven clean matches: R101, R102, R106, R107, R108, R109 and R110. Their signed total on each side is 570.49 FC. They consume seven rows from A and seven from B. Residue: three A rows, four B rows, four reference groups.

Reference | A rows | B rows | A subtotal | B subtotal | B minus A
R103 | A03 | B03 B04 | 240.00 | 480.00 | +240.00
R104 | A04 | absent | 60.00 | 0.00 | -60.00
R105 | A05 | B05 | 180.25 | 182.25 | +2.00
R111 | absent | B11 | 0.00 | 40.00 | +40.00
Residue |  |  | 480.25 | 702.25 | +222.00

Coverage check: 570.49 + 480.25 = 1,050.74 for A; 570.49 + 702.25 = 1,272.74 for B. Bridge: +240.00 - 60.00 + 2.00 + 40.00 = +222.00. All raw rows are accounted for exactly once.

R103: S1 confirms an extra export row, not a duplicate payment. R104: present only in A; absence from B is observed, cause unresolved. R105: same reference, differing amounts; neither amount is established as correct. R111: present only in B; cause unresolved. S2 establishes that the two 75.00 items are distinct, so keep both.

If a reviewer creates a separately labelled practice view excluding B04 under S1, B becomes 1,032.74 FC and B minus A becomes -18.00 FC. This explains the export repeat but does not resolve the remaining three groups. Raw data must remain available. This derived view is not a corrected real ledger.

# Handoff and teaching review

## Example checked handoff

I compared 10 A rows with 11 B rows for the fictional PRACTICE account on 3 November 2026. Seven reference groups match one-to-one, totalling 570.49 FC on each side. The raw difference B minus A is +222.00 FC. R103 contributes +240.00, R104 -60.00, R105 +2.00 and R111 +40.00. S1 establishes B04 as an extra export row. The causes and authoritative values for the other three groups remain unresolved. Both 75.00 items are retained under S2. No source records have been changed.

## Check your reasoning

A repeated amount is not a repeated item: removing either R108 or R109 would lose a valid distinct record. Ignoring -25.00 changes each raw total by +25.00 and can hide a sign error even while the difference remains unchanged. Adding 222.00 solely to balance the files invents a record. A numeric bridge can be complete while the underlying causes remain unknown.

## What counts as a successful practice attempt

Your work preserves the raw inputs, covers all 21 rows, identifies seven clean matches and four exception groups, reproduces the signed totals, explains S1 and S2 narrowly, and leaves S3 unresolved. If any check fails, correct the calculation or wording and retain a note of your first answer. No score, certificate or job-readiness claim follows from this small exercise.

