Office Calculator Pro is an Android calculator app designed for office and finance tasks. With its virtual tape, the app allows you to switch between calculator view and tape view for a full-screen view of the tape. The virtual tape can have up to 1000 lines, which is more than enough for most calculations. This app supports commercial rounding, easy percentage calculation, and correct tax calculation.

The app also provides a corrections feature on the virtual tape that allows you to make changes to the values entered. Additionally, the percentage calculation feature allows you to add or subtract percentage values, and the tape displays the percentage and the resulting value. The calculator also has tax buttons to add or subtract tax amounts. The tape displays the tax rate and the resulting value. You can write comments on each tape line to annotate your calculations.

The fixed-point arithmetic has 20 digits and 0-4 decimal places, while the floating-point arithmetic has 64 bits (IEEE double precision). The calculator supports three rounding modes: up, down, or 5/4. The Pro version is available without ads, and a free version with ads is also available for users to download.