For most types of attribute queries it is faster to look up a record. Set the Parser to Python. When you upgrade Portal for ArcGIS 102 to a later version the legacy behavior persists.
Set the Parser to Python.
Paste the following into the Pre-Logic Script Code. Select Calculate Values 91 and previous or Field Calculator 92 and later. Adding Consecutive Numbers by using a easy and simple math trick is described step by step with a well guidance included with more practice. If calculating an existing field make sure it is a Long Integer Type.