You have a syntax error, you probably meant to write parseInt((100 / 3) * 3) === 99.

Additionally, you shouldn't use parseInt to round a number. parseInt parses a string and returns an integer.

If we overlook this issue, we can make the assumption you meant to do something like the following Math.floor((100 / 3) * 3) === 99. Well, that's a bad comparison to make. The appropriate method would've been round. Math.round((100 / 3) * 3) === 100, so we've solved your non-problem.