GLM 5.2 vs GPT-5.5 for bookkeeping

**1. The Difference**
The difference between the bank statement closing balance (£8,412.55) and the cash book closing balance (£8,376.55) is **£36.00**. 

**2. Kind of Error**
This is a **transposition error**. Specifically, the figures £451.00 and £415.00 have been transposed. The bookkeeper has entered £451.00 in the cash book where she should have entered £415.00 (or vice versa, but the cash book balance is lower, meaning a receipt is understated or a payment is overstated). 

**3. The Arithmetic Rule**
The rule that identifies this class of…

Adjusted bank statement balance:

- Bank statement closing balance: **£8,412.55**
- Less unpresented cheque: **£120.00**
- Add lodgement not yet credited: **£120.00**

These cancel, so adjusted bank balance remains **£8,412.55**.

Cash book balance: **£8,376.55**

So the difference is:

**£8,412.55 − £8,376.55 = £36.00**

The bank is **£36.00 higher** than the cash book.

This is the classic sign of a **transposition error**: **£451** and **£415** have been interchanged.

Arithmetic rule: a transposition error is usually divisible by **9**. Her…