Switch methods on the same data and watch one add to the balance while the other adjusts to it.
Credit sales $400,000 × 1% = expense $4,000.
Existing allowance $650 + expense $4,000 = new allowance $4,650.
$4,000
$4,650
Sales method — expense $4,000, allowance $4,650 · Receivables method — expense $4,500, allowance $5,150
Touch the instrument to see what to notice.