Row 3 is the balance held for the beginning of the month J3 & K3: no formulas
Row 4 is cash coming in (D4) so only the cash amount changes, formula used in K5 is =IF(OR(ISBLANK(A5),ISBLANK(B5)),"",IF((H5+I5)=0,D5+K4-F5,K4-H5+I5))
Row 5 is cash gong out F5 so only the cash amount changes, formula is the same above.
Row 6 is a Cheque going out, so is listed as an expenditure F6 and a withdrawal from the bank balance I6, The bank balance should change but the cash amount K6 should not.
Row 7 is a Cheque Coming in, so is list as an income D7 and a deposit into the bank balance H7. The bank balance should change but not the cash amount.
Row 8 is a transfer from the cash K8 to the bank balance J8, so the deposit in H8 should make the bank balance increase J8 and the cash amount should decrease K8
Row 9 is a transfer from the bank balance J9 to cash K9, so the withdrawal in I9 should make bank balance decrease J9 and the cash amount should increase K9
This simple cash book is turning out to be anything but simple.