diff --git a/checks/testing/testing10.py b/checks/testing/testing10.py
index 190d471..df37d68 100644
--- a/checks/testing/testing10.py
+++ b/checks/testing/testing10.py
@@ -4,6 +4,10 @@
 src = inspect.getsource(test_sum_list)
 assert src.count("assert") >= 5, "test_sum_list should contain at least 5 assertions"
 # spot-check the empty-list edge case
-assert sum_list([]) == 0
-assert sum_list([-1, -2]) == -3
+empty_sum = sum_list([])
+assert empty_sum == 0, "sum_list([]) should be 0, got %r" % empty_sum
+negative_sum = sum_list([-1, -2])
+assert negative_sum == -3, (
+    "sum_list([-1, -2]) should be -3, got %r" % negative_sum
+)
 print("testing10 ✓")
diff --git a/checks/testing/testing8.py b/checks/testing/testing8.py
index 9da9ab6..0070883 100644
--- a/checks/testing/testing8.py
+++ b/checks/testing/testing8.py
@@ -21,7 +21,16 @@ def _code(fn):
 assert len(cases) >= 3, "cases should hold at least 3 (input, expected) pairs"
 
 # run a direct spot check
-assert abs(fahrenheit_to_celsius(32) - 0.0) < 1e-6
-assert abs(fahrenheit_to_celsius(212) - 100.0) < 1e-6
-assert abs(fahrenheit_to_celsius(-40) - (-40.0)) < 1e-6
+celsius_32 = fahrenheit_to_celsius(32)
+assert abs(celsius_32 - 0.0) < 1e-6, (
+    "fahrenheit_to_celsius(32) should be 0.0, got %r" % celsius_32
+)
+celsius_212 = fahrenheit_to_celsius(212)
+assert abs(celsius_212 - 100.0) < 1e-6, (
+    "fahrenheit_to_celsius(212) should be 100.0, got %r" % celsius_212
+)
+celsius_minus40 = fahrenheit_to_celsius(-40)
+assert abs(celsius_minus40 - (-40.0)) < 1e-6, (
+    "fahrenheit_to_celsius(-40) should be -40.0, got %r" % celsius_minus40
+)
 print("testing8 ✓")