diff --git a/test/browser/every-test.html b/test/browser/every-test.html
index 70702de..57c86c9 100644
--- a/test/browser/every-test.html
+++ b/test/browser/every-test.html
@@ -21,6 +21,7 @@
           'cmp',
           'config',
           'div',
+          'dp',
           'floor',
           'minus',
           'mod',
diff --git a/test/browser/single-test.html b/test/browser/single-test.html
index d51da42..05462f8 100644
--- a/test/browser/single-test.html
+++ b/test/browser/single-test.html
@@ -14,6 +14,7 @@
   <!-- <script src='../config.js'></script>        -->
   <!-- <script src='../cmp.js'></script>           -->
   <!-- <script src='../div.js'></script>           -->
+  <!-- <script src='../dp.js'></script>           -->
   <!-- <script src='../floor.js'></script>         -->
   <!-- <script src='../minus.js'></script>         -->
   <!-- <script src='../mod.js'></script>           -->
diff --git a/test/dp.js b/test/dp.js
new file mode 100644
index 0000000..7bb7d66
--- /dev/null
+++ b/test/dp.js
@@ -0,0 +1,94 @@
+var count = (function dp(BigNumber) {
+    var start = +new Date(),
+        log,
+        error,
+        passed = 0,
+        total = 0;
+
+    if (typeof window === 'undefined') {
+        log = console.log;
+        error = console.error;
+    } else {
+        log = function (str) { document.body.innerHTML += str.replace('\n', '<br>') };
+        error = function (str) { document.body.innerHTML += '<div style="color: red">' +
+          str.replace('\n', '<br>') + '</div>' };
+    }
+
+    if (!BigNumber && typeof require === 'function') BigNumber = require('../bignumber');
+
+    function assert(expected, actual) {
+        total++;
+        if (expected !== actual) {
+           error('\n Test number: ' + total + ' failed');
+           error(' Expected: ' + expected);
+           error(' Actual:   ' + actual);
+           //process.exit();
+        }
+        else {
+            passed++;
+            //log('\n Expected and actual: ' + actual);
+        }
+    }
+
+    function T(value, dp){
+        assert(dp, new BigNumber(value).decimalPlaces());
+        assert(dp, new BigNumber(value).dp());
+    }
+
+    log('\n Testing dp...');
+
+    BigNumber.config({
+        DECIMAL_PLACES : 20,
+        ROUNDING_MODE : 4,
+        ERRORS : true,
+        RANGE : 1E9,
+        EXPONENTIAL_AT : [-7, 21]
+    });
+
+    T(0, 0);
+    T(1, 0);
+    T(1.2, 1);
+    T(0.1, 1);
+    T(0.25, 2);
+    T(0.0625, 4);
+    T(99, 0);
+    T(9900, 0);
+    T(1000.001, 3);
+    T('1000.001', 3);
+    T(-0, 0);
+    T(-1, 0);
+    T(-1.2, 1);
+    T(-0.1, 1);
+    T(-0.25, 2);
+    T(-0.0625, 4);
+    T(-99, 0);
+    T(-9900, 0);
+    T(-1000.001, 3);
+    T('-1000.001', 3);
+
+    T(NaN, null);
+    T('NaN', null);
+    T(Infinity, null);
+    T(-Infinity, null);
+    T('Infinity', null);
+    T('-Infinity', null);
+
+    T('0.00000000000000000002', 20);
+    T('100.0000000000000000000000000000000000032948', 40);
+    T('1.3e-11', 12);
+    T('-3.52e-7', 9);
+    T('6.9525e-12', 16);
+    T('2.1e-8', 9);
+    T('3.7015e-7', 11);
+    T('-50.1839', 4);
+    T('0.014836', 6);
+    T('-16688', 0);
+    T('-506006218906684823229.56892808849303', 14);
+    T('10000000000000.00000000000000000000000000000000000001000000000000000000000000000000000000000001', 80);
+    T('057643758687043658032465987410000000000000.0000000000000', 0);
+    T('999999999999999999999999999999999999999999999999999999999999999999999999999.99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999', 113);
+
+    log('\n ' + passed + ' of ' + total + ' tests passed in ' + (+new Date() - start) + ' ms \n');
+    return [passed, total];;
+})(this.BigNumber);
+if (typeof module !== 'undefined' && module.exports) module.exports = count;
\ No newline at end of file
diff --git a/test/every-test.js b/test/every-test.js
index 754e702..b1cf48d 100644
--- a/test/every-test.js
+++ b/test/every-test.js
@@ -12,6 +12,7 @@ console.log( '\n STARTING TESTS...\n' );
   'ceil',
   'cmp',
   'config',
+  'dp',
   'div',
   'floor',
   'minus',