diff --git a/pyproject.toml b/pyproject.toml
index cfa5f73..280d899 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,7 +30,7 @@ classifiers = [
 requires-python = ">=3.10"
 dependencies = [
     "asteval",
-    "bumps",
+    "bumps<1.0.0",
     "DFO-LS",
     "lmfit",
     "numpy",  
diff --git a/src/easyscience/variable/descriptor_number.py b/src/easyscience/variable/descriptor_number.py
index 1b1e257..66f0e7a 100644
--- a/src/easyscience/variable/descriptor_number.py
+++ b/src/easyscience/variable/descriptor_number.py
@@ -299,9 +299,15 @@ def __repr__(self) -> str:
         string = '<'
         string += self.__class__.__name__ + ' '
         string += f"'{self._name}': "
-        string += f'{self._scalar.value:.4f}'
-        if self.variance:
-            string += f' \u00b1 {self.error:.4f}'
+        if np.abs(self._scalar.value)>1e4 or (np.abs(self._scalar.value)<1e-4 and self._scalar.value != 0):
+            # Use scientific notation for large or small values
+            string += f'{self._scalar.value:.3e}'
+            if self.variance:
+                string += f' \u00b1 {self.error:.3e}'
+        else:
+            string += f'{self._scalar.value:.4f}'
+            if self.variance:
+                string += f' \u00b1 {self.error:.4f}'
         obj_unit = self._scalar.unit
         if obj_unit == 'dimensionless':
             obj_unit = ''
@@ -485,4 +491,4 @@ def _base_unit(self) -> str:
                     return string[i:]
             elif letter not in ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.', '+', '-']:
                 return string[i:]
-        return ''
\ No newline at end of file
+        return ''