I've noticed that import changes numbers slightly. For example, 0.417 becomes 0.416999999999. What is causing this to happen?

I've noticed that import changes numbers slightly. For example, 0.417 becomes 0.416999999999. What is causing this to happen?

[John D'Errico]

0.417 is a number that does not exist in a BINARY floating point form, so it is stored as

0.4169999999999999817923423961474327370524406433105468750

Answer 1

[Star Strider]

You’re seeing floating-point approximation error.

A recent discussion: Why do inconsistencies exist with floating-point numbers rounding in sprintf, fprintf, sin etc?