diff --git a/exercises/practice/roman-numerals/.docs/instructions.md b/exercises/practice/roman-numerals/.docs/instructions.md
index bb7e909..247ea08 100644
--- a/exercises/practice/roman-numerals/.docs/instructions.md
+++ b/exercises/practice/roman-numerals/.docs/instructions.md
@@ -36,6 +36,6 @@ In Roman numerals 1990 is MCMXC:
 2000=MM
 8=VIII
 
-Learn more about [Roman numberals on Wikipedia][roman-numerals].
+Learn more about [Roman numerals on Wikipedia][roman-numerals].
 
 [roman-numerals]: https://wiki.imperivm-romanvm.com/wiki/Roman_Numerals
diff --git a/exercises/practice/roman-numerals/.meta/tests.toml b/exercises/practice/roman-numerals/.meta/tests.toml
index 630a42c..57c6c4b 100644
--- a/exercises/practice/roman-numerals/.meta/tests.toml
+++ b/exercises/practice/roman-numerals/.meta/tests.toml
@@ -30,6 +30,9 @@ description = "6 is VI"
 [ff3fb08c-4917-4aab-9f4e-d663491d083d]
 description = "9 is IX"
 
+[6d1d82d5-bf3e-48af-9139-87d7165ed509]
+description = "16 is XVI"
+
 [2bda64ca-7d28-4c56-b08d-16ce65716cf6]
 description = "27 is XXVII"
 
@@ -42,6 +45,9 @@ description = "49 is XLIX"
 [d5b283d4-455d-4e68-aacf-add6c4b51915]
 description = "59 is LIX"
 
+[4465ffd5-34dc-44f3-ada5-56f5007b6dad]
+description = "66 is LXVI"
+
 [46b46e5b-24da-4180-bfe2-2ef30b39d0d0]
 description = "93 is XCIII"
 
@@ -51,17 +57,32 @@ description = "141 is CXLI"
 [267f0207-3c55-459a-b81d-67cec7a46ed9]
 description = "163 is CLXIII"
 
+[902ad132-0b4d-40e3-8597-ba5ed611dd8d]
+description = "166 is CLXVI"
+
 [cdb06885-4485-4d71-8bfb-c9d0f496b404]
 description = "402 is CDII"
 
 [6b71841d-13b2-46b4-ba97-dec28133ea80]
 description = "575 is DLXXV"
 
+[dacb84b9-ea1c-4a61-acbb-ce6b36674906]
+description = "666 is DCLXVI"
+
 [432de891-7fd6-4748-a7f6-156082eeca2f]
 description = "911 is CMXI"
 
 [e6de6d24-f668-41c0-88d7-889c0254d173]
 description = "1024 is MXXIV"
 
+[efbe1d6a-9f98-4eb5-82bc-72753e3ac328]
+description = "1666 is MDCLXVI"
+
 [bb550038-d4eb-4be2-a9ce-f21961ac3bc6]
 description = "3000 is MMM"
+
+[3bc4b41c-c2e6-49d9-9142-420691504336]
+description = "3001 is MMMI"
+
+[4e18e96b-5fbb-43df-a91b-9cb511fe0856]
+description = "3999 is MMMCMXCIX"
diff --git a/exercises/practice/roman-numerals/test.sml b/exercises/practice/roman-numerals/test.sml
index 0cc97af..cdca40b 100644
--- a/exercises/practice/roman-numerals/test.sml
+++ b/exercises/practice/roman-numerals/test.sml
@@ -1,4 +1,4 @@
-(* version 1.0.0 *)
+(* version 1.1.0 *)
 
 use "testlib.sml";
 use "roman-numerals.sml";
@@ -8,59 +8,83 @@ fun x |> f = f x
 
 val testsuite =
   describe "roman-numerals" [
-    test "1 is a single I"
+    test "1 is I"
       (fn _ => roman (1) |> Expect.equalTo "I"),
 
-    test "2 is two I's"
+    test "2 is II"
       (fn _ => roman (2) |> Expect.equalTo "II"),
 
-    test "3 is three I's"
+    test "3 is III"
       (fn _ => roman (3) |> Expect.equalTo "III"),
 
-    test "4, being 5 - 1, is IV"
+    test "4 is IV"
       (fn _ => roman (4) |> Expect.equalTo "IV"),
 
-    test "5 is a single V"
+    test "5 is V"
       (fn _ => roman (5) |> Expect.equalTo "V"),
 
-    test "6, being 5 + 1, is VI"
+    test "6 is VI"
       (fn _ => roman (6) |> Expect.equalTo "VI"),
 
-    test "9, being 10 - 1, is IX"
+    test "9 is IX"
       (fn _ => roman (9) |> Expect.equalTo "IX"),
 
-    test "20 is two X's"
+    test "16 is XVI"
+      (fn _ => roman (16) |> Expect.equalTo "XVI"),
+
+    test "27 is XXVII"
       (fn _ => roman (27) |> Expect.equalTo "XXVII"),
 
-    test "48 is not 50 - 2 but rather 40 + 8"
+    test "48 is XLVIII"
       (fn _ => roman (48) |> Expect.equalTo "XLVIII"),
 
-    test "50 is a single L"
+    test "49 is XLIX"
+      (fn _ => roman (49) |> Expect.equalTo "XLIX"),
+
+    test "59 is LIX"
       (fn _ => roman (59) |> Expect.equalTo "LIX"),
 
-    test "90, being 100 - 10, is XC"
+    test "66 is LXVI"
+      (fn _ => roman (66) |> Expect.equalTo "LXVI"),
+
+    test "93 is XCIII"
       (fn _ => roman (93) |> Expect.equalTo "XCIII"),
 
-    test "100 is a single C"
+    test "141 is CXLI"
       (fn _ => roman (141) |> Expect.equalTo "CXLI"),
 
-    test "60, being 50 + 10, is LX"
+    test "163 is CLXIII"
       (fn _ => roman (163) |> Expect.equalTo "CLXIII"),
 
-    test "400, being 500 - 100, is CD"
+    test "166 is CLXVI"
+      (fn _ => roman (166) |> Expect.equalTo "CLXVI"),
+
+    test "402 is CDII"
       (fn _ => roman (402) |> Expect.equalTo "CDII"),
 
-    test "500 is a single D"
+    test "575 is DLXXV"
       (fn _ => roman (575) |> Expect.equalTo "DLXXV"),
 
-    test "900, being 1000 - 100, is CM"
+    test "666 is DCLXVI"
+      (fn _ => roman (666) |> Expect.equalTo "DCLXVI"),
+
+    test "911 is CMXI"
       (fn _ => roman (911) |> Expect.equalTo "CMXI"),
 
-    test "1000 is a single M"
+    test "1024 is MXXIV"
       (fn _ => roman (1024) |> Expect.equalTo "MXXIV"),
 
-    test "3000 is three M's"
-      (fn _ => roman (3000) |> Expect.equalTo "MMM")
+    test "1666 is MDCLXVI"
+      (fn _ => roman (1666) |> Expect.equalTo "MDCLXVI"),
+
+    test "3000 is MMM"
+      (fn _ => roman (3000) |> Expect.equalTo "MMM"),
+
+    test "3001 is MMMI"
+      (fn _ => roman (3001) |> Expect.equalTo "MMMI"),
+
+    test "3999 is MMMCMXCIX"
+      (fn _ => roman (3999) |> Expect.equalTo "MMMCMXCIX")
   ]
 
 val _ = Test.run testsuite
\ No newline at end of file