diff --git a/tools/math.py b/tools/math.py
new file mode 100644
index 0000000..92ad48c
--- /dev/null
+++ b/tools/math.py
@@ -0,0 +1,7 @@
+from decimal import Decimal, ROUND_HALF_UP
+from .types import Numeric
+
+
+def round_half_up(number: Numeric) -> int:
+    """ pythons round() rounds .5 to the *even* number; 0.5 == 0 """
+    return int(Decimal(number).to_integral(ROUND_HALF_UP))