woocs_precision_on_calc
Needed if prices are very low. For example, paper clips are sold at $0.000423 and the minimum order is from 10,000. In order not to fall exactly during the conversion, it is worth transferring
add_filter('woocs_precision_on_calc', function ($precision, $currency) {
$precision = 6;
return $precision;
}, 10, 2);