diff --git a/src/app/components/DisplayResultView.jsx b/src/app/components/DisplayResultView.jsx
index 72c1943..6508e09 100644
--- a/src/app/components/DisplayResultView.jsx
+++ b/src/app/components/DisplayResultView.jsx
@@ -9,7 +9,7 @@ import ExpressionResultView from './results/ExpressionResultView';
 import WhatsnewResult from '../models/WhatsnewResult';
 import WhatsnewResultView from './results/WhatsnewResultView';
 import ErrorResult from '../models/ErrorResult';
-import expression from '../../expression';
+import * as expression from '../expression';
 
 export default class DisplayResult extends React.Component {
     render() {
@@ -22,18 +22,6 @@ export default class DisplayResult extends React.Component {
                     </div>;
     }
 
-    renderUnknown() {
-        return <div className="result">
-                    <div className="error">¯\_(ツ)_/¯ Sorry, i don&prime;t know what <strong>{this.props.input}</strong> is</div>
-               </div>
-    }
-
-    renderError(message) {
-        return <div className="result">
-                    <div className="error">(X_X) Error occurred: <strong>{message}</strong></div>
-               </div>
-    }
-
     findResultComponent(result) {
         if(result instanceof HelpResult) {
             return <HelpResultView content={result} />
@@ -51,14 +39,14 @@ export default class DisplayResult extends React.Component {
             return <WhatsnewResultView />
         }
 
-        if (result instanceof expression.ExpressionError) {
-            return this.renderError(result.message);
+        if (result instanceof ErrorResult) {
+            return <div className="result">
+                    <div className="error">(X_X) Ooops.. Something ain' right: <strong>{result.error.message}</strong></div>
+               </div>
         }
 
-        if (result instanceof Error) {
-            return this.renderError(result.message);
-        }
-
-        return this.renderUnknown();
+        return <div className="result">
+                    <div className="error">¯\_(ツ)_/¯ Sorry, i don&prime;t know what <strong>{this.props.input}</strong> is</div>
+               </div>
     }
 }
\ No newline at end of file
diff --git a/src/app/expression.js b/src/app/expression.js
index 1b78fcc..5c3786f 100644
--- a/src/app/expression.js
+++ b/src/app/expression.js
@@ -1,4 +1,6 @@
 import Operand from './expression/operand';
+export { default as Operand } from './expression/operand';
+export { default as ExpressionError } from './expression/ExpressionError';
 
 var expression = {
         factories:[],
diff --git a/src/app/expression/Operand.js b/src/app/expression/Operand.js
index 4f86cb9..ab74189 100644
--- a/src/app/expression/Operand.js
+++ b/src/app/expression/Operand.js
@@ -72,7 +72,7 @@ export default class Operand {
             var parsed = numberParser.parse(input);
 
             if(!parsed) {
-                throw new ExpressionError("Unknown number: " + input);
+                throw new ExpressionError(input + " is not a valid number");
             }
 
             return new Operand(parsed);
diff --git a/tests/unit/hashSpec.js b/tests/unit/hashSpec.js
index 93c0401..3ace81c 100644
--- a/tests/unit/hashSpec.js
+++ b/tests/unit/hashSpec.js
@@ -30,28 +30,10 @@ describe('hash arguments parser', function() {
         expect(args.commands).toEqual(['clear', '16 15', '16&15']);
     });
 
-    it('should parse multiple commands url encoded', function() {
-        var args = hash.getArgs('#' + encodeURI('1|2||1^2||~2'));
-        expect(args).not.toBe(null);
-        expect(args).toBeDefined();
-        expect(args.commands).toEqual(['1|2', '1^2', '~2']);
-    });
-
-    it('should parse multiple commands and switcher encoded', function() {
+    it('should parse multiple commands encoded', function() {
         var args = hash.getArgs('#' + encodeURI('1|2||1^2||~2||-notrack||-debug'));
         expect(args).not.toBe(null);
         expect(args).toBeDefined();
-        expect(args.commands).toEqual(['1|2', '1^2', '~2']);
-        expect(args.notrack).toBe(true);
-        expect(args.debug).toBe(true);
-    });
-
-    it('should parse only switchers encoded', function() {
-        var args = hash.getArgs('#' + encodeURI('-notrack||-debug'));
-        expect(args).not.toBe(null);
-        expect(args).toBeDefined();
-        expect(args.commands).toEqual([]);
-        expect(args.notrack).toBe(true);
-        expect(args.debug).toBe(true);
+        expect(args.commands).toEqual(['1|2', '1^2', '~2','-notrack','-debug']);
     });
 });
\ No newline at end of file
diff --git a/tests/unit/operandSpec.js b/tests/unit/operandSpec.js
index 95d4989..ccaa39e 100644
--- a/tests/unit/operandSpec.js
+++ b/tests/unit/operandSpec.js
@@ -4,15 +4,15 @@ var parser = expression.parser;
 describe("operand", function() {
     it("should be able to create opearand from positive binary string", function() {
         var input = "0b10";
-        var op = new expression.Operand(input);
+        var op = new expression.Operand.parse(input);
         expect(op.value).toBe(2);
-        expect(op.kind).toBe('dec');
+        expect(op.kind).toBe('bin');
     });
 
     it("should be able to create opearand from negative binary string", function() {
         var input = "-0b10";
-        var op = new expression.Operand(input);
+        var op = new expression.Operand.parse(input);
         expect(op.value).toBe(-2);
-        expect(op.kind).toBe('dec');
+        expect(op.kind).toBe('bin');
     })
 });