HOW VOLUME CONVERSIONS ARE DONE?
On the calculator there are conversions of capacity (gallons (US or UK) to liters, liters to gallons (Us), gallons(UK) but there are no conversions from ft^3 to m^3. However you have the basic conversions from in to cm, cm to in, yd to m and m to yd. That is all you need.
To use the calculator to perform a conversion from ft to meters, you enter the number of feet, you press [SHIFT] (Conv).
The calculator prompts you to enter a number between 01 and 40. Each number corresponds to a particular conversion. In this case you enter 03
For example convert 3 ft to meters.
Press [SHIFT] (Conv)
Prompt: CONVERSION Number 01--40
You enter 03 (ft to m) and press [=]
Calculator displays 3 ft >m, and on the second line 0.9144
Thus 3 ft=0.9144 m
Once you know how to convert one unit of length to another, you get the volume by raising conversion to the 3rd power.
For this to work, you must convert all dimensions to the same unit.