> along with decimal floating point

Source? I'd find this a bit strange because:

1. I suspect decimal floating point is quite expensive to implement computationally.

2. Not an expert, but I think the floating-point algorithms and proofs for bases other than 2 are less well researched and less well known.

3. A calculator is a resource-constrained device.

4. Are there even any real benefits? Yes, some human-friendly numbers have an exact finite representation that is missing in base-2, but I can't see why would that matter, compared to just using 32-bit or 64-bit IEEE-754.