Here's a practical example that comes to mind. I work in film and we deal with frame rates. Often tools use 24 or 30 frames per second. 30fps is a simplifica

Here's a practical example that comes to mind. I work in film and we deal with frame rates. Often tools use 24 or 30 frames per second. 30fps is a simplification of 60 frames interlaced, which is technically 29.97fps. The main use-case we have is storing, comparing, and occasionally flipping between fractions and decimals. You would think integers would work. We've tried to update our tools to use 29.97 when it is necessary (although, this spans Python, databases, and third-party applications). The first attempt used floats, but we'd have scenarios where we'd get 24.00001 or errors comparing two values. The second attempt just used strings for frame rate so comparisons and storage work and you have a lookup table when you need to convert. Decimal sounds like a better solution. A similar scenario in film (that hasn't caused as much trouble for me) is aspect ratio, which is the height/width of an image. Fractions and decimals are used interchangeably in conversation.