diff --git a/tests/test_catmath.py b/tests/test_catmath.py
index ced6358..f6dea46 100644
--- a/tests/test_catmath.py
+++ b/tests/test_catmath.py
@@ -2,18 +2,35 @@
 
 
 def test__cat_years_to_hooman_years__middle_age__succeeds():
-    assert True
+    cat_age = 7
+    hooman_age = catmath.cat_years_to_hooman_years(cat_age)
+    assert hooman_age == 35
 
 
 def test__cat_years_to_hooman_years__less_than_one_year__succeeds():
-    assert True
+    cat_age = 0.1
+    hooman_age = catmath.cat_years_to_hooman_years(cat_age)
+    assert hooman_age == 0.5
 
 
 def test__cat_years_to_hooman_years__0__returns_0():
-    assert True
+    hooman_age = catmath.cat_years_to_hooman_years(0)
+    assert hooman_age == 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__not_divisible_by_4__isnt_leap_year():
+    assert catmath.is_cat_leap_year(1757) is False
+
+
+def test__is_cat_leap_year__divisible_by_100__isnt_leap_year():
+    assert catmath.is_cat_leap_year(1900) is False
+
+
+def test__is_cat_leap_year__centurial_leap_year__is_leap_year():
+    assert catmath.is_cat_leap_year(2000) is True
+
+
+def test__is_cat_leap_year__typical_leap_year__is_leap_year():
+    assert catmath.is_cat_leap_year(2004) is True