Modularize master branch.

math.default.js

@@ -0,0 +1,21 @@
+import add from './add.js';
+import ceil from './ceil.js';
+import divide from './divide.js';
+import floor from './floor.js';
+import max from './max.js';
+import maxBy from './maxBy.js';
+import mean from './mean.js';
+import meanBy from './meanBy.js';
+import min from './min.js';
+import minBy from './minBy.js';
+import multiply from './multiply.js';
+import round from './round.js';
+import subtract from './subtract.js';
+import sum from './sum.js';
+import sumBy from './sumBy.js';
+
+export default {
+  add, ceil, divide, floor, max,
+  maxBy, mean, meanBy, min, minBy,
+  multiply, round, subtract, sum, sumBy
+};