Ah, round-to-even makes sense, I should have realized that but was thinking it would be some messy floating-point thing. (This gets used in banking because it’s a form of rounding that doesn’t systematically bias the resulting numbers in either direction).
And just now I thought, wait, wouldn’t this sometimes round to 10, but no, an AI explained to apparently-stupid me again that since it’s a 0.25 tax rate on integer goods, fractional gold pieces before rounding (where not a multiple of 0.1) can only be 0.25, which rounds down to 2 silver, or 0.75, which rounds up to 8 silver. Which makes it all the more surprising that I didn’t notice this pattern.
Ah, round-to-even makes sense, I should have realized that but was thinking it would be some messy floating-point thing. (This gets used in banking because it’s a form of rounding that doesn’t systematically bias the resulting numbers in either direction).
And just now I thought, wait, wouldn’t this sometimes round to 10, but no, an AI explained to apparently-stupid me again that since it’s a 0.25 tax rate on integer goods, fractional gold pieces before rounding (where not a multiple of 0.1) can only be 0.25, which rounds down to 2 silver, or 0.75, which rounds up to 8 silver. Which makes it all the more surprising that I didn’t notice this pattern.