Done

index.js

@@ -0,0 +1,35 @@
+function add(num1, num2) {
+  return parseInt(num1 + num2)
+}
+
+function subtract(num1, num2) {
+  return parseInt(num1 - num2)
+}
+
+function multiply(num1, num2) {
+  return parseInt(num1 * num2)
+}
+
+function divide(num1, num2) {
+  return num1 / num2
+}
+
+function increment(n) {
+  n += 1
+  return n
+}
+
+function decrement(n) {
+  n -= 1
+  return n
+}
+
+function makeInt(n) {
+  return parseInt(n, 10)
+}
+
+function preserveDecimal(n) {
+  return parseFloat(n)
+}
+
+console.log(increment(1))