npm and error messages

node_modules/core-js/library/modules/es7.math.fscale.js

@@ -0,0 +1,10 @@
+// https://rwaldron.github.io/proposal-math-extensions/
+var $export = require('./_export');
+var scale = require('./_math-scale');
+var fround = require('./_math-fround');
+
+$export($export.S, 'Math', {
+  fscale: function fscale(x, inLow, inHigh, outLow, outHigh) {
+    return fround(scale(x, inLow, inHigh, outLow, outHigh));
+  }
+});