diff --git a/Cargo.toml b/Cargo.toml
index 8c299ad..2927311 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,8 @@ authors = ["The Rust Project Developers"]
 description = "A collection of numeric types and traits for Rust, including bigint,\ncomplex, rational, range iterators, generic integers, and more!\n"
 documentation = "http://rust-num.github.io/num"
 homepage = "https://github.com/rust-num/num"
-keywords = ["mathematics", "numerics"]
+keywords = ["mathematics", "numerics", "bignum"]
+categories = [ "algorithms", "data-structures", "science" ]
 license = "MIT/Apache-2.0"
 repository = "https://github.com/rust-num/num"
 name = "num"
diff --git a/bigint/Cargo.toml b/bigint/Cargo.toml
index f8129de..bc7c4c2 100644
--- a/bigint/Cargo.toml
+++ b/bigint/Cargo.toml
@@ -3,7 +3,8 @@ authors = ["The Rust Project Developers"]
 description = "Big integer implementation for Rust"
 documentation = "http://rust-num.github.io/num"
 homepage = "https://github.com/rust-num/num"
-keywords = ["mathematics", "numerics"]
+keywords = ["mathematics", "numerics", "bignum"]
+categories = [ "algorithms", "data-structures", "science" ]
 license = "MIT/Apache-2.0"
 name = "num-bigint"
 repository = "https://github.com/rust-num/num"
diff --git a/complex/Cargo.toml b/complex/Cargo.toml
index 86a0972..8a89c0b 100644
--- a/complex/Cargo.toml
+++ b/complex/Cargo.toml
@@ -4,6 +4,7 @@ description = "Complex numbers implementation for Rust"
 documentation = "http://rust-num.github.io/num"
 homepage = "https://github.com/rust-num/num"
 keywords = ["mathematics", "numerics"]
+categories = [ "algorithms", "data-structures", "science" ]
 license = "MIT/Apache-2.0"
 name = "num-complex"
 repository = "https://github.com/rust-num/num"
diff --git a/derive/Cargo.toml b/derive/Cargo.toml
index 53fff4e..d7d04e9 100644
--- a/derive/Cargo.toml
+++ b/derive/Cargo.toml
@@ -4,6 +4,7 @@ description = "Numeric syntax extensions"
 documentation = "http://rust-num.github.io/num"
 homepage = "https://github.com/rust-num/num"
 keywords = ["mathematics", "numerics"]
+categories = [ "science" ]
 license = "MIT/Apache-2.0"
 name = "num-derive"
 repository = "https://github.com/rust-num/num"
diff --git a/integer/Cargo.toml b/integer/Cargo.toml
index 5fa53c0..b21bfd1 100644
--- a/integer/Cargo.toml
+++ b/integer/Cargo.toml
@@ -4,6 +4,7 @@ description = "Integer traits and functions"
 documentation = "http://rust-num.github.io/num"
 homepage = "https://github.com/rust-num/num"
 keywords = ["mathematics", "numerics"]
+categories = [ "algorithms", "science" ]
 license = "MIT/Apache-2.0"
 repository = "https://github.com/rust-num/num"
 name = "num-integer"
diff --git a/iter/Cargo.toml b/iter/Cargo.toml
index afc7e6b..aa26742 100644
--- a/iter/Cargo.toml
+++ b/iter/Cargo.toml
@@ -4,6 +4,7 @@ description = "External iterators for generic mathematics"
 documentation = "http://rust-num.github.io/num"
 homepage = "https://github.com/rust-num/num"
 keywords = ["mathematics", "numerics"]
+categories = [ "algorithms", "science" ]
 license = "MIT/Apache-2.0"
 repository = "https://github.com/rust-num/num"
 name = "num-iter"
diff --git a/macros/Cargo.toml b/macros/Cargo.toml
index ba8b442..2bdbd4f 100644
--- a/macros/Cargo.toml
+++ b/macros/Cargo.toml
@@ -7,6 +7,7 @@ homepage = "https://github.com/rust-num/num"
 repository = "https://github.com/rust-num/num"
 documentation = "http://rust-num.github.io/num"
 keywords = ["mathematics", "numerics"]
+categories = [ "science" ]
 description = "Numeric syntax extensions"
 
 [lib]
diff --git a/rational/Cargo.toml b/rational/Cargo.toml
index 5a4f280..0f9e678 100644
--- a/rational/Cargo.toml
+++ b/rational/Cargo.toml
@@ -4,6 +4,7 @@ description = "Rational numbers implementation for Rust"
 documentation = "http://rust-num.github.io/num"
 homepage = "https://github.com/rust-num/num"
 keywords = ["mathematics", "numerics"]
+categories = [ "algorithms", "data-structures", "science" ]
 license = "MIT/Apache-2.0"
 name = "num-rational"
 repository = "https://github.com/rust-num/num"
diff --git a/traits/Cargo.toml b/traits/Cargo.toml
index 7fdf99d..498e71e 100644
--- a/traits/Cargo.toml
+++ b/traits/Cargo.toml
@@ -4,6 +4,7 @@ description = "Numeric traits for generic mathematics"
 documentation = "http://rust-num.github.io/num"
 homepage = "https://github.com/rust-num/num"
 keywords = ["mathematics", "numerics"]
+categories = [ "algorithms", "science" ]
 license = "MIT/Apache-2.0"
 repository = "https://github.com/rust-num/num"
 name = "num-traits"