Gemini 3.1 Pro Preview vs Grok 4.5 for bookkeeping

**1. Work out the difference**
The bank statement closing balance is £8,412.55. 
The cash book closing balance is £8,376.55. 
The difference is **£36.00** (£8,412.55 - £8,376.55). 
*(Note: The outstanding unpresented cheque and uncredited lodgement of £120.00 perfectly cancel each other out, so they do not affect this £36.00 difference).*

**2. What kind of error is it?**
This is a **transposition error** (specifically, reversing two adjacent digits when recording a number). 

**3. The arithmetic rule that identifies this class of error at a gl…

The balances differ by £36 (bank higher than cash book).  

This is a transposition error (digits reversed in one amount: 415.00 vs 451.00).  

Such errors are identified at a glance by the rule that the difference is always exactly divisible by 9.  

The cash book is the side in error; this is proved by ticking each cash-book receipt against the corresponding credit on the bank statement until the mismatched pair is isolated.  

Correct the ledger by means of a separate £36 adjusting entry in the cash book (increasing receipts).  
Do **not** a…