I am having trouble figuring out how to round a number to the nearest ones place in p5.js

I have a game I’m making in p5.js and I am having trouble rounding my health varible to the nearest ones place.

I tried using p5.js’s round() function (https://p5js.org/reference/p5/round/) and it isn’t fitting my problem. I don’t think you can use the round() function for variables, I think you use it for just strings.