This application works as a linear interpolations calculator. It allows the use of a table when the exact value you look for it is omitted in this table through an interpolation between two known values.
An extrapolation is possible when the statistics table does not go far enough.
This is a very frequent problem when you have to use statistics tables. The application is designed to be easy manipulated with a mobile phone or a tablet.
The example is taken from the table of expectancy life in the area of Social Security, as shown in the link:
https://www.ssa.gov/oact/STATS/table4c6.html