Hence, an increase in asset values is recorded on the Dr (left) side and a reduction on the Cr (right) side, whereas conversely an increase in Liabilities or Owners' Claims is recorded on the Cr (right) side and a reduction on the Dr (left) side. Then, provided for each transaction the Dr entry equals the Cr entry the accounting equation will remain in balance - hence a 'double-entry' system. Also, the sum of all Dr entries will remain equal to the sum of all Cr entries - thus providing a partial check on inaccurate record-keeping or arithmetic (this could be confirmed by producing a report called a 'Trial Balance' showing all Dr and Cr balances at a specific point in time - a necessary preliminary to preparing a set of accounts).

The underlying logic, and the terminology used in this system lives on in computerised systems, and although arithmetic accuracy, and balance can be maintained by the computer, it is still necessary for accountants to understand, and be able to apply this ancient system of transaction record-keeping to trace and correct human errors and understand the effect of, and correctly enter complex transactions or accounting adjustments.