diff --git a/index.js b/index.js
index e69de29bb2..b58d30cd7c 100644
--- a/index.js
+++ b/index.js
@@ -0,0 +1,31 @@
+function add (a, b) {
+  return a + b;
+}
+
+function subtract (a, b) {
+  return a - b;
+}
+
+function multiply (a, b) {
+  return a * b;
+}
+
+function divide (a, b) {
+  return a / b;
+}
+
+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);
+}