When your app performs math that results in a decimal number, the stored value may not be exactly what you'd expect. This is a fundamental limitation of how computers represent decimal numbers using binary floating-point arithmetic — certain decimals can't be stored with perfect precision, which causes small rounding errors.
What you might notice
A calculation that should produce a specific decimal produces a slightly different result
The ":rounded to" operator doesn't always round as expected — for example, "2100.055 rounded to 2" may return "2100.05" instead of "2100.06"
Results vary slightly from what a standard calculator would show
Workaround
For specific use cases, consider working in whole numbers and converting at the point of display — for example, storing a price in cents rather than dollars, then dividing by 100 when you display it. This reduces the number of decimal operations and minimises the risk of rounding errors accumulating.