diff --git a/binder/requirements.txt b/binder/requirements.txt
index db18772..0080c1b 100644
--- a/binder/requirements.txt
+++ b/binder/requirements.txt
@@ -1,6 +1,7 @@
 matplotlib
 networkx>=2.0,<2.7
 numpy
+numpy-financial
 openpyxl>=2.6.2
 python-dateutil
 pydot
diff --git a/setup.py b/setup.py
index c560d05..40c13d5 100644
--- a/setup.py
+++ b/setup.py
@@ -63,6 +63,7 @@ def changes():
     install_requires=[
         'networkx>=2.0,<2.7',
         'numpy',
+        'numpy-financial',
         'openpyxl>=2.6.2',
         'python-dateutil',
         'ruamel.yaml',
diff --git a/src/pycel/lib/financial.py b/src/pycel/lib/financial.py
new file mode 100644
index 0000000..7e6b8f6
--- /dev/null
+++ b/src/pycel/lib/financial.py
@@ -0,0 +1,35 @@
+# -*- coding: UTF-8 -*-
+#
+# Copyright 2011-2019 by Dirk Gorissen, Stephen Rauch and Contributors
+# All rights reserved.
+# This file is part of the Pycel Library, Licensed under GPLv3 (the 'License')
+# You may not use this work except in compliance with the License.
+# You may obtain a copy of the Licence at:
+#   https://www.gnu.org/licenses/gpl-3.0.en.html
+
+"""
+Python equivalents of Excel financial functions
+"""
+import numpy_financial as npf
+
+from pycel.excelutil import flatten
+
+
+def irr(values, guess=None):
+    # Excel reference: https://support.microsoft.com/en-us/office/
+    #   irr-function-64925eaa-9988-495b-b290-3ad0c163c1bc
+
+    # currently guess is not used
+    return npf.irr(list(flatten(values)))
+
+
+def pmt(rate, nper, pv, fv=0, when=0):
+    # Excel reference: https://support.microsoft.com/en-us/office/
+    #   pmt-function-0214da64-9a63-4996-bc20-214433fa6441
+    return npf.pmt(rate, nper, pv, fv=fv, when=when)
+
+
+def ppmt(rate, per, nper, pv, fv=0, when=0):
+    # Excel reference: https://support.microsoft.com/en-us/office/
+    #   ppmt-function-c370d9e3-7749-4ca4-beea-b06c6ac95e1b
+    return npf.ppmt(rate, per, nper, pv, fv=fv, when=when)
diff --git a/src/pycel/lib/lookup.py b/src/pycel/lib/lookup.py
index 0c25b2d..d835e42 100644
--- a/src/pycel/lib/lookup.py
+++ b/src/pycel/lib/lookup.py
@@ -13,6 +13,7 @@
 from bisect import bisect_right
 
 import numpy as np
+from openpyxl.utils import get_column_letter
 
 from pycel.excelutil import (
     AddressCell,
@@ -141,9 +142,19 @@ def compare(idx, val):
     return result[0]
 
 
-# def address(value):
+def address(row_num, column_num, abs_num=1, style=None, sheet_text=''):
     # Excel reference: https://support.microsoft.com/en-us/office/
     #   address-function-d0c26c0d-3991-446b-8de4-ab46431d4f89
+    sheet_text = "'" + sheet_text + "'!" if sheet_text else sheet_text
+    if style == 0:
+        r = str(row_num) if abs_num in [1, 2] else str([row_num])
+        c = str(column_num) if abs_num in [1, 3] else str([column_num])
+        return f'{sheet_text}R{r}C{c}'
+    else:
+        abs_row = '$' if abs_num in [1, 2] else ''
+        abs_col = '$' if abs_num in [1, 3] else ''
+        return f'{sheet_text}{abs_col}{get_column_letter(column_num)}' \
+               f'{abs_row}{str(row_num)}'
 
 
 # def areas(value):
@@ -174,14 +185,38 @@ def column(ref):
         return ref.col_idx
 
 
-# def columns(value):
+def columns(values):
     # Excel reference: https://support.microsoft.com/en-us/office/
     #   columns-function-4e8e7b4e-e603-43e8-b177-956088fa48ca
+    if list_like(values):
+        return len(values[0])
+    return 1
 
 
-# def filter(value):
+def _xlws_filter(values, include, if_empty=VALUE_ERROR):
     # Excel reference: https://support.microsoft.com/en-us/office/
     #   filter-function-f4f7cb66-82eb-4767-8f7c-4877ad80c759
+    if not list_like(include):
+        if not isinstance(values, tuple) or len(values) == 1 or len(values[0]) == 1:
+            return values if include else if_empty
+        return if_empty
+
+    res = None
+    if len(values[0]) == len(include[0]) and not len(include) > 1:
+        transpose = tuple(col for col in zip(*values))
+        res = [transpose[i] for i in range(len(transpose))
+               if include[0][i]]
+        res = tuple([col for col in zip(*res)])
+
+    elif len(values) == len(include) and not len(include[0]) > 1:
+        res = tuple([values[i] for i in range(len(values))
+                    if include[i][0]])
+
+    if res:
+        return res
+    if res is None:
+        return VALUE_ERROR
+    return if_empty
 
 
 # def formulatext(value):
@@ -431,9 +466,12 @@ def row(ref):
         return ref.row
 
 
-# def rows(value):
+def rows(values):
     # Excel reference: https://support.microsoft.com/en-us/office/
     #   rows-function-b592593e-3fc2-47f2-bec1-bda493811597
+    if list_like(values):
+        return len(values)
+    return 1
 
 
 # def rtd(value):
diff --git a/src/pycel/lib/stats.py b/src/pycel/lib/stats.py
index cb41935..da8a2ac 100644
--- a/src/pycel/lib/stats.py
+++ b/src/pycel/lib/stats.py
@@ -185,14 +185,31 @@ def count(*args):
                if isinstance(x, (int, float)) and not isinstance(x, bool))
 
 
-# def counta(value):
+def counta(*args):
     # Excel reference: https://support.microsoft.com/en-us/office/
     #   counta-function-7dc98875-d5c1-46f1-9a82-53f3219e2509
+    res = 0
+    for arg in args:
+        if list_like(arg):
+            for row in arg:
+                for cell in row:
+                    res = res + 1 if cell is not None else res
+        else:
+            res = res + 1 if arg else res
+    return res
 
 
-# def countblank(value):
+def countblank(values):
     # Excel reference: https://support.microsoft.com/en-us/office/
     #   countblank-function-6a92d772-675c-4bee-b346-24af6bd3ac22
+    res = 0
+    if list_like(values):
+        for row in values:
+            for cell in row:
+                res = res + 1 if cell in [None, ''] else res
+    else:
+        res = 1 if values in [None, ''] else res
+    return res
 
 
 def countif(rng, criteria):
diff --git a/tests/fixtures/filter.xlsx b/tests/fixtures/filter.xlsx
new file mode 100644
index 0000000..9771b09
Binary files /dev/null and b/tests/fixtures/filter.xlsx differ
diff --git a/tests/lib/test_financial.py b/tests/lib/test_financial.py
new file mode 100644
index 0000000..388a3b4
--- /dev/null
+++ b/tests/lib/test_financial.py
@@ -0,0 +1,61 @@
+# -*- coding: UTF-8 -*-
+#
+# Copyright 2011-2021 by Dirk Gorissen, Stephen Rauch and Contributors
+# All rights reserved.
+# This file is part of the Pycel Library, Licensed under GPLv3 (the 'License')
+# You may not use this work except in compliance with the License.
+# You may obtain a copy of the Licence at:
+#   https://www.gnu.org/licenses/gpl-3.0.en.html
+
+import math
+
+import pytest
+
+from pycel.lib.financial import (
+    irr,
+    pmt,
+    ppmt
+)
+
+
+@pytest.mark.parametrize(
+    'values, guess, expected',
+    (
+        ((-100, -50, 100, 200, 400), None, 0.671269),
+        ((-70000, 12000, 15000, 18000, 21000, 26000),
+         None, 0.086631),
+        ((-70000, 12000, 15000, 18000, 21000),
+         None, -0.021245),
+        ((-70000, 12000, 15000), 0.10, -0.443507)
+    )
+)
+def test_irr(values, guess, expected):
+    assert math.isclose(irr(values, guess=guess),
+                        expected, abs_tol=1e-4)
+
+
+@pytest.mark.parametrize(
+    'rate, nper, pv, fv, when, expected',
+    (
+        (0.05, 12, 100, 400, 0, -36.412705),
+        (0.00667, 10, 10000, 0, 0, -1037.050788),
+        (0.00667, 10, 10000, 0, 1, -1030.179490),
+        (0.005, 216, 0, 50000, 0, -129.0811609)
+    )
+)
+def test_pmt(rate, nper, pv, fv, when, expected):
+    assert math.isclose(pmt(rate, nper, pv, fv, when),
+                        expected, abs_tol=1e-4)
+
+
+@pytest.mark.parametrize(
+    'rate, per, nper, pv, fv, when, expected',
+    (
+        (0.05, 12, 100, 400, 0, 0, -0.262118),
+        (0.00833, 1, 24, 2000, 0, 0, -75.626160),
+        (0.08, 10, 10, 200000, 0, 0, -27598.053460)
+    )
+)
+def test_ppmt(rate, per, nper, pv, fv, when, expected):
+    assert math.isclose(ppmt(rate, per, nper, pv, fv, when),
+                        expected, abs_tol=1e-4)
diff --git a/tests/lib/test_lookup.py b/tests/lib/test_lookup.py
index 0c80525..57536a2 100644
--- a/tests/lib/test_lookup.py
+++ b/tests/lib/test_lookup.py
@@ -26,8 +26,10 @@
 from pycel.lib.function_helpers import error_string_wrapper, load_to_test_module
 from pycel.lib.lookup import (
     _match,
+    address,
     choose,
     column,
+    columns,
     hlookup,
     index,
     indirect,
@@ -35,6 +37,7 @@
     match,
     offset,
     row,
+    rows,
     vlookup,
 )
 
@@ -72,6 +75,24 @@ def test_lookup_ws(fixture_xls_copy):
     assert indirect == 8
 
 
+@pytest.mark.parametrize(
+    'row_num, col_num, abs_num, style, sheet_text, expected',
+    (
+        (2, 3, 1, None, '', '$C$2'),
+        (2, 3, 3, None, '', '$C2'),
+        (2, 3, 2, None, '', 'C$2'),
+        (2, 3, 2, False, '', 'R2C[3]'),
+        (2, 3, 2, True, '', 'C$2'),
+        (5, 4, 4, True, 'Sheet1', '\'Sheet1\'!D5'),
+        (5, 4, 1, True, 'Sheet1', '\'Sheet1\'!$D$5'),
+        (5, 4, 1, None, 'Sheet1', '\'Sheet1\'!$D$5'),
+        (5, 4, 1, False, 'Sheet1', '\'Sheet1\'!R5C4'),
+    )
+)
+def test_address(row_num, col_num, abs_num, style, sheet_text, expected):
+    assert address(row_num, col_num, abs_num, style, sheet_text) == expected
+
+
 @pytest.mark.parametrize(
     'index, data, expected', (
         (-1, 'ABCDEFG', VALUE_ERROR),
@@ -122,6 +143,25 @@ def test_column(address, expected):
         assert expected == result
 
 
+@pytest.mark.parametrize(
+    'values, expected', (
+        (((1, None, None), (1, 2, None)), 3),
+        (1, 1),
+        ("s", 1),
+        (((1.2, 3.4), (0.4, 5)), 2),
+        (((None, None, None, None,), ), 4)
+    )
+)
+def test_columns(values, expected):
+    assert columns(values) == expected
+
+
+def test_xlws_filter(fixture_xls_copy):
+    compiler = ExcelCompiler(fixture_xls_copy('filter.xlsx'))
+    result = compiler.validate_serialized()
+    assert result == {}
+
+
 @pytest.mark.parametrize(
     'lkup, row_idx, result, approx', (
         ('A', 0, VALUE_ERROR, True),
@@ -566,6 +606,20 @@ def test_row(address, expected):
         assert expected == result
 
 
+@pytest.mark.parametrize(
+    'values, expected', (
+        (((1, None, None), (1, 2, None)), 2),
+        (1, 1),
+        ("s", 1),
+        (((1.2, 3.4), (0.4, 5)), 2),
+        (((None, None,), ), 1),
+        (((1,), (2,), (3,)), 3)
+    )
+)
+def test_rows(values, expected):
+    assert rows(values) == expected
+
+
 @pytest.mark.parametrize(
     'lkup, col_idx, result, approx', (
         ('A', 0, VALUE_ERROR, True),
diff --git a/tests/lib/test_stats.py b/tests/lib/test_stats.py
index 55bd170..d7865a3 100644
--- a/tests/lib/test_stats.py
+++ b/tests/lib/test_stats.py
@@ -32,6 +32,8 @@
     averageif,
     averageifs,
     count,
+    counta,
+    countblank,
     countif,
     countifs,
     forecast,
@@ -124,6 +126,33 @@ def test_count():
     assert count(data, data[3], data[5], data[7])
 
 
+@pytest.mark.parametrize(
+    'values, expected', (
+        ((((7, 0, 1, None), ), ), 3),
+        ((((True, False, 0, ''), ), ), 4),
+        ((True, ), 1),
+        ((((False, NA_ERROR, VALUE_ERROR), ), ), 3),
+        (((('', None, 4), (NAME_ERROR, True, 0)), ), 5),
+        (((('', None, 4), ), 7, ((4, ), (5, )), 10), 6),
+    )
+)
+def test_counta(values, expected):
+    assert counta(*values) == expected
+
+
+@pytest.mark.parametrize(
+    'values, expected', (
+        (((7, 0, 1, None), ), 1),
+        (((True, False, 0, ''), ), 1),
+        (False, 0),
+        (((False, NA_ERROR, None), ), 1),
+        ((('', None, 4), (NAME_ERROR, True, 0)), 2),
+    )
+)
+def test_countblank(values, expected):
+    assert countblank(values) == expected
+
+
 @pytest.mark.parametrize(
     'value, criteria, expected', (
         (((7, 25, 13, 25), ), '>10', 3),