diff --git a/tests/BCMathHelperTest.php b/tests/BCMathHelperTest.php
new file mode 100644
index 0000000..6903186
--- /dev/null
+++ b/tests/BCMathHelperTest.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Ksdev\NBPCurrencyConverter\Test;
+
+use Ksdev\NBPCurrencyConverter\BCMathHelper;
+
+class BCMathHelperTest extends \PHPUnit_Framework_TestCase
+{
+    public function testBcround()
+    {
+        $this->assertEquals('0.5679', BCMathHelper::bcround('0.567891', 4));
+        $this->assertEquals('0.5676', BCMathHelper::bcround('0.567591', 4));
+        $this->assertEquals('0.5676', BCMathHelper::bcround('0.567559', 4));
+        $this->assertEquals('0.5675', BCMathHelper::bcround('0.567544', 4));
+    }
+}
diff --git a/tests/NBPCurrencyConverterTest.php b/tests/NBPCurrencyConverterTest.php
index b2aaf4c..e27593b 100644
--- a/tests/NBPCurrencyConverterTest.php
+++ b/tests/NBPCurrencyConverterTest.php
@@ -26,6 +26,8 @@ public function testConvert()
     {
         $converter = new NBPCurrencyConverter($this->guzzleMock(), null, 0);
 
+        $this->assertEquals('0.2651', $converter->convert('1.0000', 'PLN', 'USD')['amount']);
+        $this->assertEquals('3.7726', $converter->convert('1.0000', 'USD', 'PLN')['amount']);
         $this->assertEquals('123.4567', $converter->convert('123.4567', 'PLN', 'PLN')['amount']);
         $this->assertEquals('32.7246', $converter->convert('123.4567', 'PLN', 'USD')['amount']);
         $this->assertEquals('465.7527', $converter->convert('123.4567', 'USD', 'PLN')['amount']);
@@ -38,6 +40,10 @@ public function testConvert()
         $this->assertEquals('284.0662', $converter->convert('123.4567', 'JPY', 'HUF')['amount']);
         $this->assertEquals('53.6549', $converter->convert('123.4567', 'HUF', 'JPY')['amount']);
         $this->assertEquals('123.4567', $converter->convert('123.4567', 'JPY', 'JPY')['amount']);
+        $this->assertEquals('53654981.1634', $converter->convert('123456789.6789', 'HUF', 'JPY')['amount']);
+        $this->assertEquals('284066429.3850', $converter->convert('123456789.6789', 'JPY', 'HUF')['amount']);
+        $this->assertEquals('32724590.3830', $converter->convert('123456789.6789', 'PLN', 'USD')['amount']);
+        $this->assertEquals('465753084.7426', $converter->convert('123456789.6789', 'USD', 'PLN')['amount']);
     }
 
     public function testInvalidFormatOfAmount()