diff --git a/publik_django_templatetags/publik/templatetags/publik.py b/publik_django_templatetags/publik/templatetags/publik.py
index d56990f..26932bc 100644
--- a/publik_django_templatetags/publik/templatetags/publik.py
+++ b/publik_django_templatetags/publik/templatetags/publik.py
@@ -14,8 +14,14 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import math
+from decimal import Decimal
+from decimal import DivisionByZero as DecimalDivisionByZero
+from decimal import InvalidOperation as DecimalInvalidOperation
+
 from django import template
 from django.template import defaultfilters
+from django.utils.encoding import force_text
 
 register = template.Library()
 
@@ -48,6 +54,11 @@ def as_list(obj):
     return list(obj)
 
 
+@register.filter
+def split(string, separator=' '):
+    return (force_text(string) or '').split(separator)
+
+
 @register.filter
 def first(value):
     try:
@@ -62,3 +73,89 @@ def last(value):
         return defaultfilters.last(value)
     except TypeError:
         return ''
+
+
+def parse_decimal(value, default=Decimal(0)):
+    if isinstance(value, str):
+        # replace , by . for French users comfort
+        value = value.replace(',', '.')
+    try:
+        return Decimal(value).quantize(Decimal('1.0000')).normalize()
+    except (ArithmeticError, TypeError):
+        return default
+
+
+@register.filter(is_safe=False)
+def decimal(value, arg=None):
+    if not isinstance(value, Decimal):
+        value = parse_decimal(value)
+    if arg is None:
+        return value
+    return defaultfilters.floatformat(value, arg=arg)
+
+
+@register.filter
+def add(term1, term2):
+    '''replace the "add" native django filter'''
+
+    if term1 is None:
+        term1 = ''
+    if term2 is None:
+        term2 = ''
+    term1_decimal = parse_decimal(term1, default=None)
+    term2_decimal = parse_decimal(term2, default=None)
+
+    if term1_decimal is not None and term2_decimal is not None:
+        return term1_decimal + term2_decimal
+    if term1 == '' and term2_decimal is not None:
+        return term2_decimal
+    if term2 == '' and term1_decimal is not None:
+        return term1_decimal
+    return defaultfilters.add(term1, term2)
+
+
+@register.filter
+def subtract(term1, term2):
+    return parse_decimal(term1) - parse_decimal(term2)
+
+
+@register.filter
+def multiply(term1, term2):
+    return parse_decimal(term1) * parse_decimal(term2)
+
+
+@register.filter
+def divide(term1, term2):
+    try:
+        return parse_decimal(term1) / parse_decimal(term2)
+    except DecimalInvalidOperation:
+        return ''
+    except DecimalDivisionByZero:
+        return ''
+
+
+@register.filter
+def ceil(value):
+    '''the smallest integer value greater than or equal to value'''
+    return decimal(math.ceil(parse_decimal(value)))
+
+
+@register.filter
+def floor(value):
+    return decimal(math.floor(parse_decimal(value)))
+
+
+@register.filter(name='abs')
+def abs_(value):
+    return decimal(abs(parse_decimal(value)))
+
+
+@register.filter(name='sum')
+def sum_(list_):
+    if isinstance(list_, str):
+        # do not consider string as iterable, to avoid misusage
+        return ''
+    try:
+        return sum(parse_decimal(term) for term in list_)
+    except TypeError:  # list_ is not iterable
+        return ''
diff --git a/tests/test_publik.py b/tests/test_publik.py
index c3dd2e7..8904b16 100644
--- a/tests/test_publik.py
+++ b/tests/test_publik.py
@@ -54,6 +54,15 @@ def test_getlist():
     assert t.render(context) == 'None,baz,'
 
 
+def test_split():
+    t = Template('{% for x in plop|split %}{{x}}<br>{% endfor %}')
+    assert t.render(Context({'plop': 'ab cd ef'})) == 'ab<br>cd<br>ef<br>'
+    t = Template('{% for x in plop|split:"|" %}{{x}} {% endfor %}')
+    assert t.render(Context({'plop': 'ab|cd|ef'})) == 'ab cd ef '
+    t = Template('{% for x in plop|split:"|" %}{{x}} {% endfor %}')
+    assert t.render(Context({'plop': 42})) == '42 '
+
+
 def test_first():
     t = Template('{{ foo|first }}')
 
@@ -84,3 +93,208 @@ def test_last():
 
     context = Context({'foo': None})
     assert t.render(context) == ''
+
+
+def test_decimal():
+    tmpl = Template('{{ plop|decimal }}')
+    assert tmpl.render(Context({'plop': 'toto'})) == '0'
+    assert tmpl.render(Context({'plop': '3.14'})) == '3.14'
+    assert tmpl.render(Context({'plop': '3,14'})) == '3.14'
+    assert tmpl.render(Context({'plop': 3.14})) == '3.14'
+    assert tmpl.render(Context({'plop': 12345.678})) == '12345.678'
+    assert tmpl.render(Context({'plop': None})) == '0'
+    assert tmpl.render(Context({'plop': 0})) == '0'
+
+    tmpl = Template('{{ plop|decimal:3 }}')
+    assert tmpl.render(Context({'plop': '3.14'})) == '3.140'
+    assert tmpl.render(Context({'plop': None})) == '0.000'
+    tmpl = Template('{{ plop|decimal:"3" }}')
+    assert tmpl.render(Context({'plop': '3.14'})) == '3.140'
+    assert tmpl.render(Context({'plop': None})) == '0.000'
+
+    tmpl = Template('{% if plop|decimal > 2 %}hello{% endif %}')
+    assert tmpl.render(Context({'plop': 3})) == 'hello'
+    assert tmpl.render(Context({'plop': '3'})) == 'hello'
+    assert tmpl.render(Context({'plop': 2.001})) == 'hello'
+    assert tmpl.render(Context({'plop': '2.001'})) == 'hello'
+    assert tmpl.render(Context({'plop': 1})) == ''
+    assert tmpl.render(Context({'plop': 1.99})) == ''
+    assert tmpl.render(Context({'plop': '1.99'})) == ''
+    assert tmpl.render(Context({'plop': 'x'})) == ''
+    assert tmpl.render(Context({'plop': None})) == ''
+    assert tmpl.render(Context({'plop': 0})) == ''
+
+    tmpl = Template('{% if "3"|decimal == 3 %}hello{% endif %}')
+    assert tmpl.render(Context()) == 'hello'
+    tmpl = Template('{% if "3"|decimal == 3.0 %}hello{% endif %}')
+    assert tmpl.render(Context()) == 'hello'
+    tmpl = Template('{% if 3|decimal == 3 %}hello{% endif %}')
+    assert tmpl.render(Context()) == 'hello'
+    tmpl = Template('{% if 3.0|decimal == 3 %}hello{% endif %}')
+    assert tmpl.render(Context()) == 'hello'
+    tmpl = Template('{% if 3|decimal|decimal == 3 %}hello{% endif %}')
+    assert tmpl.render(Context()) == 'hello'
+
+
+def test_add():
+    tmpl = Template('{{ term1|add:term2 }}')
+
+    # using strings
+    assert tmpl.render(Context({'term1': '1.1', 'term2': 0})) == '1.1'
+    assert tmpl.render(Context({'term1': 'not a number', 'term2': 1.2})) == ''
+    assert tmpl.render(Context({'term1': 0.3, 'term2': "1"})) == '1.3'
+    assert tmpl.render(Context({'term1': 1.4, 'term2': "not a number"})) == ''
+
+    # add
+    assert tmpl.render(Context({'term1': 4, 'term2': -0.9})) == '3.1'
+    assert tmpl.render(Context({'term1': '4', 'term2': -0.8})) == '3.2'
+    assert tmpl.render(Context({'term1': 4, 'term2': '-0.7'})) == '3.3'
+    assert tmpl.render(Context({'term1': '4', 'term2': '-0.6'})) == '3.4'
+    assert tmpl.render(Context({'term1': '', 'term2': 3.5})) == '3.5'
+    assert tmpl.render(Context({'term1': None, 'term2': 3.5})) == '3.5'
+    assert tmpl.render(Context({'term1': 3.6, 'term2': ''})) == '3.6'
+    assert tmpl.render(Context({'term1': '', 'term2': ''})) == ''
+    assert tmpl.render(Context({'term1': 3.6, 'term2': None})) == '3.6'
+    assert tmpl.render(Context({'term1': 0, 'term2': ''})) == '0'
+    assert tmpl.render(Context({'term1': '', 'term2': 0})) == '0'
+    assert tmpl.render(Context({'term1': 0, 'term2': 0})) == '0'
+
+    # if term is '' or None and other term is decimal
+    assert tmpl.render(Context({'term1': '', 'term2': 2.2})) == '2.2'
+    assert tmpl.render(Context({'term1': None, 'term2': 2.2})) == '2.2'
+    assert tmpl.render(Context({'term1': 2.2, 'term2': ''})) == '2.2'
+    assert tmpl.render(Context({'term1': 2.2, 'term2': None})) == '2.2'
+
+    # add using ',' instead of '.' decimal separator
+    assert tmpl.render(Context({'term1': '1,1', 'term2': '2,2'})) == '3.3'
+    assert tmpl.render(Context({'term1': '1,1', 'term2': '2.2'})) == '3.3'
+    assert tmpl.render(Context({'term1': '1,1', 'term2': 2.2})) == '3.3'
+    assert tmpl.render(Context({'term1': '1,1', 'term2': 0})) == '1.1'
+    assert tmpl.render(Context({'term1': '1,1', 'term2': ''})) == '1.1'
+    assert tmpl.render(Context({'term1': '1,1', 'term2': None})) == '1.1'
+    assert tmpl.render(Context({'term1': '1.1', 'term2': '2,2'})) == '3.3'
+    assert tmpl.render(Context({'term1': 1.1, 'term2': '2,2'})) == '3.3'
+    assert tmpl.render(Context({'term1': 0, 'term2': '2,2'})) == '2.2'
+    assert tmpl.render(Context({'term1': '', 'term2': '2,2'})) == '2.2'
+    assert tmpl.render(Context({'term1': None, 'term2': '2,2'})) == '2.2'
+
+    # fallback to Django native add filter
+    assert tmpl.render(Context({'term1': 'foo', 'term2': 'bar'})) == 'foobar'
+    assert tmpl.render(Context({'term1': 'foo', 'term2': ''})) == 'foo'
+    assert tmpl.render(Context({'term1': 'foo', 'term2': None})) == 'foo'
+    assert tmpl.render(Context({'term1': 'foo', 'term2': 0})) == ''
+    assert tmpl.render(Context({'term1': '', 'term2': 'bar'})) == 'bar'
+    assert tmpl.render(Context({'term1': '', 'term2': ''})) == ''
+    assert tmpl.render(Context({'term1': '', 'term2': None})) == ''
+    assert tmpl.render(Context({'term1': None, 'term2': 'bar'})) == 'bar'
+    assert tmpl.render(Context({'term1': None, 'term2': ''})) == ''
+    assert tmpl.render(Context({'term1': None, 'term2': None})) == ''
+    assert tmpl.render(Context({'term1': 0, 'term2': 'bar'})) == ''
+
+
+def test_substract():
+    tmpl = Template('{{ term1|subtract:term2 }}')
+    assert tmpl.render(Context({'term1': 5.1, 'term2': 1})) == '4.1'
+    assert tmpl.render(Context({'term1': '5.2', 'term2': 1})) == '4.2'
+    assert tmpl.render(Context({'term1': 5.3, 'term2': '1'})) == '4.3'
+    assert tmpl.render(Context({'term1': '5.4', 'term2': '1'})) == '4.4'
+    assert tmpl.render(Context({'term1': '', 'term2': -4.5})) == '4.5'
+    assert tmpl.render(Context({'term1': 4.6, 'term2': ''})) == '4.6'
+    assert tmpl.render(Context({'term1': '', 'term2': ''})) == '0'
+    assert tmpl.render(Context({'term1': 0, 'term2': ''})) == '0'
+    assert tmpl.render(Context({'term1': '', 'term2': 0})) == '0'
+    assert tmpl.render(Context({'term1': 0, 'term2': 0})) == '0'
+
+
+def test_multiply():
+    tmpl = Template('{{ term1|multiply:term2 }}')
+    assert tmpl.render(Context({'term1': '3', 'term2': '2'})) == '6'
+    assert tmpl.render(Context({'term1': 2.5, 'term2': 2})) == '5.0'
+    assert tmpl.render(Context({'term1': '2.5', 'term2': 2})) == '5.0'
+    assert tmpl.render(Context({'term1': 2.5, 'term2': '2'})) == '5.0'
+    assert tmpl.render(Context({'term1': '2.5', 'term2': '2'})) == '5.0'
+    assert tmpl.render(Context({'term1': '', 'term2': '2'})) == '0'
+    assert tmpl.render(Context({'term1': 2.5, 'term2': ''})) == '0.0'
+    assert tmpl.render(Context({'term1': '', 'term2': ''})) == '0'
+    assert tmpl.render(Context({'term1': 0, 'term2': ''})) == '0'
+    assert tmpl.render(Context({'term1': '', 'term2': 0})) == '0'
+    assert tmpl.render(Context({'term1': 0, 'term2': 0})) == '0'
+
+
+def test_divide():
+    tmpl = Template('{{ term1|divide:term2 }}')
+    assert tmpl.render(Context({'term1': 16, 'term2': 2})) == '8'
+    assert tmpl.render(Context({'term1': 6, 'term2': 0.75})) == '8'
+    assert tmpl.render(Context({'term1': '6', 'term2': 0.75})) == '8'
+    assert tmpl.render(Context({'term1': 6, 'term2': '0.75'})) == '8'
+    assert tmpl.render(Context({'term1': '6', 'term2': '0.75'})) == '8'
+    assert tmpl.render(Context({'term1': '', 'term2': '2'})) == '0'
+    assert tmpl.render(Context({'term1': 6, 'term2': ''})) == ''
+    assert tmpl.render(Context({'term1': '', 'term2': ''})) == ''
+    assert tmpl.render(Context({'term1': 0, 'term2': ''})) == ''
+    assert tmpl.render(Context({'term1': '', 'term2': 0})) == ''
+    assert tmpl.render(Context({'term1': 0, 'term2': 0})) == ''
+    tmpl = Template('{{ term1|divide:term2|decimal:2 }}')
+    assert tmpl.render(Context({'term1': 2, 'term2': 3})) == '0.67'
+
+
+def test_ceil():
+    # ceil
+    tmpl = Template('{{ value|ceil }}')
+    assert tmpl.render(Context({'value': 3.14})) == '4'
+    assert tmpl.render(Context({'value': 3.99})) == '4'
+    assert tmpl.render(Context({'value': -3.14})) == '-3'
+    assert tmpl.render(Context({'value': -3.99})) == '-3'
+    assert tmpl.render(Context({'value': 0})) == '0'
+    assert tmpl.render(Context({'value': '3.14'})) == '4'
+    assert tmpl.render(Context({'value': '3.99'})) == '4'
+    assert tmpl.render(Context({'value': '-3.14'})) == '-3'
+    assert tmpl.render(Context({'value': '-3.99'})) == '-3'
+    assert tmpl.render(Context({'value': '0'})) == '0'
+    assert tmpl.render(Context({'value': 'not a number'})) == '0'
+    assert tmpl.render(Context({'value': ''})) == '0'
+    assert tmpl.render(Context({'value': None})) == '0'
+
+
+def test_floor():
+    # floor
+    tmpl = Template('{{ value|floor }}')
+    assert tmpl.render(Context({'value': 3.14})) == '3'
+    assert tmpl.render(Context({'value': 3.99})) == '3'
+    assert tmpl.render(Context({'value': -3.14})) == '-4'
+    assert tmpl.render(Context({'value': -3.99})) == '-4'
+    assert tmpl.render(Context({'value': 0})) == '0'
+    assert tmpl.render(Context({'value': '3.14'})) == '3'
+    assert tmpl.render(Context({'value': '3.99'})) == '3'
+    assert tmpl.render(Context({'value': '-3.14'})) == '-4'
+    assert tmpl.render(Context({'value': '-3.99'})) == '-4'
+    assert tmpl.render(Context({'value': '0'})) == '0'
+    assert tmpl.render(Context({'value': 'not a number'})) == '0'
+    assert tmpl.render(Context({'value': ''})) == '0'
+    assert tmpl.render(Context({'value': None})) == '0'
+
+
+def test_abs():
+    tmpl = Template('{{ value|abs }}')
+    assert tmpl.render(Context({'value': 3.14})) == '3.14'
+    assert tmpl.render(Context({'value': -3.14})) == '3.14'
+    assert tmpl.render(Context({'value': 0})) == '0'
+    assert tmpl.render(Context({'value': '3.14'})) == '3.14'
+    assert tmpl.render(Context({'value': '-3.14'})) == '3.14'
+    assert tmpl.render(Context({'value': '0'})) == '0'
+    assert tmpl.render(Context({'value': 'not a number'})) == '0'
+    assert tmpl.render(Context({'value': ''})) == '0'
+    assert tmpl.render(Context({'value': None})) == '0'
+
+
+def test_sum():
+    t = Template('{{ "2 29.5 9,5 .5"|split|sum }}')
+    assert t.render(Context()) == '41.5'
+    t = Template('{{ list|sum }}')
+    assert t.render(Context({'list': [1, 2, '3']})) == '6'
+    assert t.render(Context({'list': [1, 2, 'x']})) == '3'
+    assert t.render(Context({'list': [None, 2.0, 'x']})) == '2'
+    assert t.render(Context({'list': []})) == '0'
+    assert t.render(Context({'list': None})) == ''  # list is not iterable
+    assert t.render(Context({'list': '123'})) == ''  # consider string as not iterable
+    assert t.render(Context()) == ''