diff --git a/README.md b/README.md
index 32dd7be..151fbae 100644
--- a/README.md
+++ b/README.md
@@ -54,8 +54,9 @@ Functions supported now.
 - [x] add
 
 ```python
-  # different from ramda, ramda treat null as 0
-  >>> R.add(None, None) # float('nan)
+# different from ramda
+R.add(None, None) # float('nan)
+R.add(date(1,2,3), date(1,2,3)) # float('nan)
 ```
 
 - [ ] addIndex
@@ -430,13 +431,20 @@ R.slice(1, None, ['a', 'b', 'c', 'd']) # ['b', 'c', 'd']
 - [x] sort
 - [x] sortBy
 - [ ] sortWith
-- [ ] split
+- [x] split
 - [ ] splitAt
 - [ ] splitEvery
 - [ ] splitWhen
 - [ ] splitWhenever
 - [ ] startsWith
-- [ ] subtract
+- [x] subtract
+
+```python
+# different from ramda
+R.subtract(None, None) # float('nan)
+R.subtract(date(1,2,3), date(1,2,3)) # float('nan)
+```
+
 - [x] sum
 - [ ] symmetricDifference
 - [ ] symmetricDifferenceWith
@@ -457,8 +465,8 @@ R.slice(1, None, ['a', 'b', 'c', 'd']) # ['b', 'c', 'd']
 
 Partially supported
 
-- String type, supported
-- for others, just use str(x) instead
+1. String type, supported
+1. for others, just use str(x) instead
 
 - [ ] toUpper
 - [ ] transduce
diff --git a/ramda/__init__.py b/ramda/__init__.py
index 7023271..6207cac 100644
--- a/ramda/__init__.py
+++ b/ramda/__init__.py
@@ -73,6 +73,8 @@
 from .slice import slice
 from .sort import sort
 from .sortBy import sortBy
+from .split import split
+from .subtract import subtract
 from .sum import sum
 from .T import T
 from .tail import tail
diff --git a/ramda/split.py b/ramda/split.py
new file mode 100644
index 0000000..329fee9
--- /dev/null
+++ b/ramda/split.py
@@ -0,0 +1,3 @@
+from .invoker import invoker
+
+split = invoker(1, 'split')
diff --git a/ramda/subtract.py b/ramda/subtract.py
new file mode 100644
index 0000000..2a3fc2f
--- /dev/null
+++ b/ramda/subtract.py
@@ -0,0 +1,4 @@
+from .private._curry2 import _curry2
+from .private._helper import toNumber
+
+subtract = _curry2(lambda a, b: toNumber(a) - toNumber(b))
diff --git a/test/test_add.py b/test/test_add.py
index f560dbd..a922512 100644
--- a/test/test_add.py
+++ b/test/test_add.py
@@ -1,5 +1,6 @@
-import math
 import unittest
+from datetime import date
+from math import isnan
 
 import ramda as R
 
@@ -16,7 +17,8 @@ def test_coerces_its_arguments_to_numbers(self):
     self.assertEqual(3, R.add('1', '2'))
     self.assertEqual(3, R.add(1, '2'))
     self.assertEqual(1, R.add(True, False))
-    self.assertTrue(math.isnan(R.add(None, None)))
+    self.assertTrue(isnan(R.add(None, None)))
+    self.assertTrue(isnan(R.add(date(1, 1, 1), date(2, 1, 1))))
 
   def test_float(self):
     self.assertEqual(4.2, R.add(1.1, 3.1))
diff --git a/test/test_split.py b/test/test_split.py
new file mode 100644
index 0000000..72d0804
--- /dev/null
+++ b/test/test_split.py
@@ -0,0 +1,19 @@
+
+import unittest
+
+import ramda as R
+
+"""
+https://github.com/ramda/ramda/blob/master/test/split.js
+"""
+
+
+class TestSplit(unittest.TestCase):
+  def test_splits_a_string_into_an_array(self):
+    self.assertEqual(['a', 'b', 'c', 'xyz', 'd'], R.split('.', 'a.b.c.xyz.d'))
+
+  def test_the_split_string_can_be_arbitrary(self):
+    self.assertEqual(['The C', ' in the H', ' s', ' on the m', ''], R.split('at', 'The Cat in the Hat sat on the mat'))
+
+if __name__ == '__main__':
+  unittest.main()
diff --git a/test/test_subtract.py b/test/test_subtract.py
new file mode 100644
index 0000000..0c772b0
--- /dev/null
+++ b/test/test_subtract.py
@@ -0,0 +1,26 @@
+
+import unittest
+from datetime import date
+from math import isnan
+
+import ramda as R
+
+"""
+https://github.com/ramda/ramda/blob/master/test/subtract.js
+"""
+
+
+class TestSubtract(unittest.TestCase):
+  def test_subtracts_two_numbers(self):
+    self.assertEqual(15, R.subtract(22, 7))
+
+  def test_coerces_its_arguments_to_numbers(self):
+    self.assertEqual(-1, R.subtract('1', '2'))
+    self.assertEqual(-1, R.subtract(1, '2'))
+    self.assertEqual(1, R.subtract(True, False))
+    self.assertTrue(isnan(R.subtract(None, None)))
+    self.assertTrue(isnan(R.subtract(date(1, 1, 1), date(2, 1, 1))))
+
+
+if __name__ == '__main__':
+  unittest.main()