Done.

Author: Zachary Goodman

index.js

@@ -0,0 +1,37 @@
+function add(a, b) {
+  var number = a+= b
+  return number
+}
+
+function subtract(a, b) {
+  var number = a -= b
+  return number
+}
+
+function multiply(a, b) {
+  var number = a *= b
+  return number
+}
+
+function divide(a, b) {
+  var number = a /= b
+  return number
+}
+
+function increment(n) {
+  n++
+  return n
+}
+
+function decrement(n) {
+  n--
+  return n
+}
+
+function makeInt(n) {
+  return parseInt(n, 10)
+}
+
+function preserveDecimal(n) {
+  return parseFloat(n)
+}