diff --git a/index.js b/index.js
index e69de29bb2..5e2d2fc1f1 100644
--- a/index.js
+++ b/index.js
@@ -0,0 +1,31 @@
+function add(x, y) {
+  return x + y
+}
+
+function subtract(x, y) {
+  return x - y
+}
+
+function multiply(x, y) {
+  return x * y
+}
+
+function divide(x, y) {
+  return x / y
+}
+
+function increment(n) {
+  return n + 1
+}
+
+function decrement(n) {
+  return n - 1
+}
+
+function makeInt(n) {
+  return parseInt(n, 10)
+}
+
+function preserveDecimal(n) {
+  return parseFloat(n)
+}