diff --git a/Calculator.java b/Calculator.java
index 492a572..031fa57 100644
--- a/Calculator.java
+++ b/Calculator.java
@@ -1,6 +1,6 @@
 public class Calculator {
     public static void main(String[] args) {
-        String expr = "(36 * 3 + 9 * 7) * (84 / 12) * 5";
+        String expr = "(84 / 4 * 3 - 9) * 2 + 1 / 5"; // 108.2
         Parser p = new Parser(expr);
         String postfix = p.toPostFix();
         System.out.println(p.evalExpr(postfix));
diff --git a/Parser.java b/Parser.java
index 8135393..c588052 100644
--- a/Parser.java
+++ b/Parser.java
@@ -1,5 +1,4 @@
 /* Todo
-* - Fix Substraction errors
 * - Add support for trigonometric functions
 * - Remove all edge cases
 */
@@ -17,6 +16,7 @@ public class Parser {
 
     public static boolean isOperand(char c) {
         switch (c) {
+            case '0':
             case '1':
             case '2':
             case '3':
@@ -115,7 +115,7 @@ public class Parser {
             case '+':
                 return op2 + op1;
             case '-':
-                return op2 - op1;
+                return op1 - op2;
             case '*':
                 return op2 * op1;
             case '/':