diff --git a/homeassistant/components/demo/number.py b/homeassistant/components/demo/number.py
index a8b9cb0ac4d..5a6ce5f5c64 100644
--- a/homeassistant/components/demo/number.py
+++ b/homeassistant/components/demo/number.py
@@ -98,7 +98,7 @@ class DemoNumber(NumberEntity):
         return self._assumed
 
     @property
-    def state(self):
+    def value(self):
         """Return the current value."""
         return self._state
 
diff --git a/homeassistant/components/number/__init__.py b/homeassistant/components/number/__init__.py
index 2fd04943e4d..31a0bcd7762 100644
--- a/homeassistant/components/number/__init__.py
+++ b/homeassistant/components/number/__init__.py
@@ -1,4 +1,5 @@
 """Component to allow numeric input for platforms."""
+from abc import abstractmethod
 from datetime import timedelta
 import logging
 from typing import Any, Dict
@@ -93,6 +94,16 @@ class NumberEntity(Entity):
                 step /= 10.0
         return step
 
+    @property
+    def state(self) -> float:
+        """Return the entity state."""
+        return self.value
+
+    @property
+    @abstractmethod
+    def value(self) -> float:
+        """Return the entity value to represent the entity state."""
+
     def set_value(self, value: float) -> None:
         """Set new value."""
         raise NotImplementedError()
diff --git a/tests/components/number/test_init.py b/tests/components/number/test_init.py
index 6037bde5afd..58e090db20f 100644
--- a/tests/components/number/test_init.py
+++ b/tests/components/number/test_init.py
@@ -1,8 +1,17 @@
 """The tests for the Number component."""
-from unittest.mock import MagicMock
-
 from homeassistant.components.number import NumberEntity
 
+from tests.async_mock import MagicMock
+
+
+class MockDefaultNumberEntity(NumberEntity):
+    """Mock NumberEntity device to use in tests."""
+
+    @property
+    def value(self):
+        """Return the current value."""
+        return 0.5
+
 
 class MockNumberEntity(NumberEntity):
     """Mock NumberEntity device to use in tests."""
@@ -13,14 +22,14 @@ class MockNumberEntity(NumberEntity):
         return 1.0
 
     @property
-    def state(self):
+    def value(self):
         """Return the current value."""
-        return "0.5"
+        return 0.5
 
 
 async def test_step(hass):
     """Test the step calculation."""
-    number = NumberEntity()
+    number = MockDefaultNumberEntity()
     assert number.step == 1.0
 
     number_2 = MockNumberEntity()
@@ -29,7 +38,7 @@ async def test_step(hass):
 
 async def test_sync_set_value(hass):
     """Test if async set_value calls sync set_value."""
-    number = NumberEntity()
+    number = MockDefaultNumberEntity()
     number.hass = hass
 
     number.set_value = MagicMock()