inch feet calculator

Scientific calculator for inch and feet calculation.
The actual formula expression .
Engineering calculations and suitable for field use .
Feature.
1. Inch and feet calculation.
2. The actual mathematical expressions .
3. Engineering and scientific calculator.
4. Fraction and Mixed Fraction input.
5. Calculation results displayed in fraction or root.
6. Differentiation function.
7. The integral function.
8. The sum of the series.
9. Unit conversion.
10. Specify functions and variables , store, use.