I worked on calorie counting software in the 00's. We had desktop software that just used floats, meanwhile the Palm Pilot software was all integer math (counting things in 10ths and 100ths when that precision was needed.)

We'd get emails about people seeing 577 calories on the Palm Pilot and 578 calories on the desktop. "None of the numbers are that accurate anyway!" was a sensible answer but not very brand aligned.