Function sum_precise 

pub fn sum_precise<I>(values: &I) -> Result<f64, JsValue>
where
    I: Iterable + ErasableGenericBorrow<JsValue>,

The Math.sumPrecise() function takes an iterable of numbers and returns their sum, computed as if with infinite precision and rounded once at the end, so it is more accurate than a naive running sum.

MDN documentation