diff --git a/Project.toml b/Project.toml
index 178e998..7a4b365 100644
--- a/Project.toml
+++ b/Project.toml
@@ -5,3 +5,9 @@ version = "0.1.0"
 
 [deps]
 Primes = "27ebfcd6-29c5-5fa9-bf4b-fb8fc14df3ae"
+
+[extras]
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[targets]
+test = ["Test"]
diff --git a/docs/Manifest.toml b/docs/Manifest.toml
new file mode 100644
index 0000000..e379175
--- /dev/null
+++ b/docs/Manifest.toml
@@ -0,0 +1,92 @@
+# This file is machine-generated - editing it directly is not advised
+
+[[Base64]]
+uuid = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
+
+[[Dates]]
+deps = ["Printf"]
+uuid = "ade2ca70-3891-5945-98fb-dc099432e06a"
+
+[[Distributed]]
+deps = ["Random", "Serialization", "Sockets"]
+uuid = "8ba89e20-285c-5b6f-9357-94700520ee1b"
+
+[[DocStringExtensions]]
+deps = ["LibGit2", "Markdown", "Pkg", "Test"]
+git-tree-sha1 = "88bb0edb352b16608036faadcc071adda068582a"
+uuid = "ffbed154-4ef7-542d-bbb7-c09d3a79fcae"
+version = "0.8.1"
+
+[[Documenter]]
+deps = ["Base64", "Dates", "DocStringExtensions", "InteractiveUtils", "JSON", "LibGit2", "Logging", "Markdown", "REPL", "Test", "Unicode"]
+git-tree-sha1 = "d497bcc45bb98a1fbe19445a774cfafeabc6c6df"
+uuid = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
+version = "0.24.5"
+
+[[InteractiveUtils]]
+deps = ["Markdown"]
+uuid = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
+
+[[JSON]]
+deps = ["Dates", "Mmap", "Parsers", "Unicode"]
+git-tree-sha1 = "b34d7cef7b337321e97d22242c3c2b91f476748e"
+uuid = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
+version = "0.21.0"
+
+[[LibGit2]]
+uuid = "76f85450-5226-5b5a-8eaa-529ad045b433"
+
+[[Libdl]]
+uuid = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
+
+[[Logging]]
+uuid = "56ddb016-857b-54e1-b83d-db4d58db5568"
+
+[[Markdown]]
+deps = ["Base64"]
+uuid = "d6f4376e-aef5-505a-96c1-9c027394607a"
+
+[[Mmap]]
+uuid = "a63ad114-7e13-5084-954f-fe012c677804"
+
+[[Parsers]]
+deps = ["Dates", "Test"]
+git-tree-sha1 = "d112c19ccca00924d5d3a38b11ae2b4b268dda39"
+uuid = "69de0a69-1ddd-5017-9359-2bf0b02dc9f0"
+version = "0.3.11"
+
+[[Pkg]]
+deps = ["Dates", "LibGit2", "Libdl", "Logging", "Markdown", "Printf", "REPL", "Random", "SHA", "Test", "UUIDs"]
+uuid = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+
+[[Printf]]
+deps = ["Unicode"]
+uuid = "de0858da-6303-5e67-8744-51eddeeeb8d7"
+
+[[REPL]]
+deps = ["InteractiveUtils", "Markdown", "Sockets"]
+uuid = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
+
+[[Random]]
+deps = ["Serialization"]
+uuid = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
+
+[[SHA]]
+uuid = "ea8e919c-243c-51af-8825-aaa63cd721ce"
+
+[[Serialization]]
+uuid = "9e88b42a-f829-5b0c-bbe9-9e923198166b"
+
+[[Sockets]]
+uuid = "6462fe0b-24de-5631-8697-dd941f90decc"
+
+[[Test]]
+deps = ["Distributed", "InteractiveUtils", "Logging", "Random"]
+uuid = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[[UUIDs]]
+deps = ["Random", "SHA"]
+uuid = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
+
+[[Unicode]]
+uuid = "4ec0a83e-493e-50e2-b9ac-8f72acf5a8f5"
diff --git a/src/NiceNumbers.jl b/src/NiceNumbers.jl
index 74cc98e..90a480a 100644
--- a/src/NiceNumbers.jl
+++ b/src/NiceNumbers.jl
@@ -1,8 +1,11 @@
 module NiceNumbers
 
-using Primes
-import Base: +, -, *, /, inv
+import Primes: factor, prodfactors
+import Base: +, -, *, /, inv, one, zero, isinteger
+import Base.promote_rule
+
 export NiceNumber
+export isrational
 
 struct NiceNumber <: Real
     a::Rational{Int}
diff --git a/test/runtests.jl b/test/runtests.jl
index e69de29..a51bf67 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -0,0 +1,43 @@
+using NiceNumbers
+using Test
+
+
+@testset "NiceNumbers" begin
+    @testset "Constructors" begin
+        @test NiceNumber(8) == NiceNumber(8, 0, 0)
+        @test NiceNumber(2, 3, 4) == NiceNumber(8)
+        @test NiceNumber(2, 3, 0) == NiceNumber(2)
+        @test NiceNumber(2, 0, 5) == NiceNumber(2)
+    end
+
+    n = NiceNumber(2, 3, 5)
+    m = NiceNumber(5, -3, 5)
+    k = NiceNumber(8, 4, 3)
+
+    @testset "Basic Arithmetic" begin
+        @test n + m == NiceNumber(7)
+        @test_broken n + k
+        @test n - m == NiceNumber(-3, 6, 5)
+        @test_broken n - k
+        @test n * m == NiceNumber(-35, 9, 5)
+        @test_broken n * k
+        @test n / m == NiceNumber(-11 // 4, -21 // 20, 5)
+        @test_broken n / k
+    end
+
+    @testset "Scalar Arithmetic" begin
+        @test 4 + n == n + 4 == NiceNumber(6, 3, 5)
+        @test 4 - n == -(n - 4) == NiceNumber(2, -3, 5)
+        @test 3 * n == n * 3 == NiceNumber(6, 9, 5)
+        @test n / 3 == inv(3 / n) == NiceNumber(2 // 3, 1, 5)
+    end
+
+    @testset "Conversion" begin
+        @test float(NiceNumber(13, 3, 7)) == 13 + 3 * √7
+    end
+
+    @testset "Misc" begin
+        @test isrational(NiceNumber(139 // 7, 0, 17))
+        @test isinteger(NiceNumber(12))
+    end
+end