diff --git a/pytest.ini b/pytest.ini
index bddc2d2..35854a4 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -1,3 +1,4 @@
 [pytest]
-addopts = --cov=catinabox --cov-report=term-missing --pep8 --flakes --mccabe
+#addopts = --cov=catinabox --cov-report=term-missing --pep8 --flakes --mccabe
+addopts = --cov=catinabox --cov-report=term-missing --flakes --mccabe
 testpaths = tests catinabox
diff --git a/tests/test_catmath.py b/tests/test_catmath.py
index ced6358..8c923c5 100644
--- a/tests/test_catmath.py
+++ b/tests/test_catmath.py
@@ -2,18 +2,37 @@
 
 
 def test__cat_years_to_hooman_years__middle_age__succeeds():
-    assert True
+    #assert True
+    assert catmath.cat_years_to_hooman_years(8) == 40 
 
 
 def test__cat_years_to_hooman_years__less_than_one_year__succeeds():
-    assert True
+    #assert True
+    assert catmath.cat_years_to_hooman_years(0.9) == 4.5
 
 
 def test__cat_years_to_hooman_years__0__returns_0():
-    assert True
+    #assert True
+    assert catmath.cat_years_to_hooman_years(0) == 0
 
 
 # BONUS MATERIAL FOR STEP 2
 
 def test__is_cat_leap_year__succeeds():
     assert catmath.is_cat_leap_year(2016) is True
+    
+def test__is_cat_leap_year_fails():
+    assert catmath.is_cat_leap_year(2023) is False
+    
+def test__is_cat_leap_year_modulo100_succeeds():
+    assert catmath.is_cat_leap_year(2000) is True
+    
+def test__is_cat_leap_year_divisible_by_100_is_not_leap_year():
+    assert catmath.is_cat_leap_year(1900) is False    
+    
+def test_is_cat_leap_year_modulo400_succeeds():
+    assert catmath.is_cat_leap_year(2400) is True
+    
+def test_is_cat_leap_year_modulo4_fails():
+    assert catmath.is_cat_leap_year(1806) is False
+    
diff --git a/tests/test_cattery.py b/tests/test_cattery.py
index b36692c..70e5a4d 100644
--- a/tests/test_cattery.py
+++ b/tests/test_cattery.py
@@ -2,14 +2,23 @@
 
 from catinabox import cattery
 
+###########################################################################
+# catery_client
+###########################################################################
+
+@pytest.fixture(scope='session')
+def cattery_client():
+    return ["Fluffy", "Snookums"]
+    
 
 ###########################################################################
 # add_cats
 ###########################################################################
 
-def test__add_cats__succeeds():
+def test__add_cats__succeeds(cattery_client):
     c = cattery.Cattery()
-    c.add_cats(["Fluffy", "Snookums"])
+    #c.add_cats(["Fluffy", "Snookums"])
+    c.add_cats(cattery_client)
     assert c.cats == ["Fluffy", "Snookums"]
     assert c.num_cats == 2
 
@@ -18,15 +27,16 @@ def test__add_cats__succeeds():
 # remove_cat
 ###########################################################################
 
-def test__remove_cat__succeeds():
+def test__remove_cat__succeeds(cattery_client):
     c = cattery.Cattery()
-    c.add_cats(["Fluffy", "Junior"])
+    #c.add_cats(["Fluffy", "Junior"])
+    c.add_cats(cattery_client)
     c.remove_cat("Fluffy")
     assert c.cats == ["Junior"]
     assert c.num_cats == 1
 
 
-def test__remove_cat__no_cats__fails():
+def test__remove_cat__no_cats__fails(cattery_client):
     c = cattery.Cattery()
     with pytest.raises(cattery.CatNotFound):
         c.remove_cat("Fluffles")
diff --git a/tests/test_safecatmath.py b/tests/test_safecatmath.py
index 3f85a35..adfbcbf 100644
--- a/tests/test_safecatmath.py
+++ b/tests/test_safecatmath.py
@@ -1,7 +1,7 @@
 # import pytest
 
 from catinabox import safecatmath
-
+import pytest
 
 def test__cat_years_to_hooman_years__middle_age__succeeds():
     hooman_age = safecatmath.cat_years_to_hooman_years(7)
@@ -19,17 +19,24 @@ def test__cat_years_to_hooman_years__0__returns_0():
 
 
 def test__cat_years_to_hooman_years__less_0__raises():
-    assert True
+    #assert True
+    with pytest.raises(safecatmath.InvalidAge):
+        safecatmath.cat_years_to_hooman_years(-10)
 
 
 def test__cat_years_to_hooman_years__older_than_1000__raises():
-    assert True
+    #assert True
+    with pytest.raises(safecatmath.InvalidAge):
+        safecatmath.cat_years_to_hooman_years(1001)
 
 
 def test__cat_years_to_hooman_years__string__raises():
-    assert True
+    with pytest.raises(safecatmath.InvalidAge):
+        safecatmath.cat_years_to_hooman_years('three')
+    #assert True
 
 
 def test__cat_years_to_hooman_years__nan__raises():
-    # hooman_age = float('nan')
-    assert True
+    hooman_age = float('nan')
+    with pytest.raises(safecatmath.InvalidAge):
+        safecatmath.cat_years_to_hooman_years(hooman_age)