diff --git a/src/decimaljs-adapter.js b/src/decimaljs-adapter.js
index 6a8da27..5ec3079 100644
--- a/src/decimaljs-adapter.js
+++ b/src/decimaljs-adapter.js
@@ -16,6 +16,12 @@ module.exports = {
   mod: mod,
   pow: pow,
   sqrt: sqrt,
+  gt: gt,
+  gte: gte,
+  lt: lt,
+  lte: lte,
+  cmp: cmp,
+  abs: abs,
   equals: equals,
   toString: toString,
   valueOf: toString,
@@ -58,6 +64,30 @@ function sqrt(x) {
   return x.sqrt();
 }
 
+function lt(x, y) {
+  return x.lt(y);
+}
+
+function lte(x, y) {
+  return x.lte(y);
+}
+
+function gt(x, y) {
+  return x.gt(y);
+}
+
+function gte(x, y) {
+  return x.gte(y);
+}
+
+function cmp(x, y) {
+  return x.cmp(y);
+}
+
+function abs(x) {
+  return x.abs();
+}
+
 function equals(x, y) {
   return x.eq(y);
 }
diff --git a/test/spec.js b/test/spec.js
index a6b6b6d..12fe594 100644
--- a/test/spec.js
+++ b/test/spec.js
@@ -7,6 +7,7 @@ var decimalFactory = require('arbitrary-precision');
 var adapter = require('../src/decimaljs-adapter');
 
 var Decimal = decimalFactory(adapter);
+var DecimalJs = adapter.getInstance();
 
 describe('arbitrary precision with decimal.js', function() {
   describe('precision', function() {
@@ -61,6 +62,41 @@ describe('arbitrary precision with decimal.js', function() {
       new Decimal('2').equals(new Decimal('2')).should.be.exactly(true);
       new Decimal('2').equals(new Decimal('3')).should.be.exactly(false);
     });
+
+    it('should have a gt method', function() {
+      adapter.gt(new Decimal('2'), new Decimal('2')).should.be.exactly(false);
+      adapter.gt(new Decimal('2'), new Decimal('3')).should.be.exactly(false);
+      adapter.gt(new Decimal('2'), new Decimal('1')).should.be.exactly(true);
+    });
+
+    it('should have a gte method', function() {
+      adapter.gte(new Decimal('2'), new Decimal('2')).should.be.exactly(true);
+      adapter.gte(new Decimal('2'), new Decimal('3')).should.be.exactly(false);
+      adapter.gte(new Decimal('2'), new Decimal('1')).should.be.exactly(true);
+    });
+
+    it('should have a lt method', function() {
+      adapter.lt(new Decimal('2'), new Decimal('2')).should.be.exactly(false);
+      adapter.lt(new Decimal('2'), new Decimal('3')).should.be.exactly(true);
+      adapter.lt(new Decimal('2'), new Decimal('1')).should.be.exactly(false);
+    });
+
+    it('should have a lte method', function() {
+      adapter.lte(new Decimal('2'), new Decimal('2')).should.be.exactly(true);
+      adapter.lte(new Decimal('2'), new Decimal('3')).should.be.exactly(true);
+      adapter.lte(new Decimal('2'), new Decimal('1')).should.be.exactly(false);
+    });
+
+    it('should have a cmp method', function() {
+      adapter.cmp(new Decimal('2'), new Decimal('2')).valueOf().should.be.exactly(0);
+      adapter.cmp(new Decimal('2'), new Decimal('3')).valueOf().should.be.exactly(-1);
+      adapter.cmp(new Decimal('2'), new Decimal('1')).valueOf().should.be.exactly(1);
+    });
+
+    it('should have a abs method', function() {
+      adapter.abs(new DecimalJs('16')).toNumber().should.be.exactly(16);
+      adapter.abs(new DecimalJs('-5')).toNumber().should.be.exactly(5);
+    });
   });
 
   describe('toString, valueOf and JSON', function() {