diff --git a/math/euclidean_algorithm.wiki b/math/euclidean_algorithm.wiki
new file mode 100644
index 0000000..cb2ebf4
--- /dev/null
+++ b/math/euclidean_algorithm.wiki
@@ -0,0 +1 @@
+= Euclidean Algorithm =
diff --git a/math/index.wiki b/math/index.wiki
index 4d76bb2..394742b 100644
--- a/math/index.wiki
+++ b/math/index.wiki
@@ -10,4 +10,5 @@ The purest study of them all
 
 * [[prime]]
 * [[relative_prime]]
-* 
+* [[modular_inverse]]
+* [[euclidean_algorithm]]
diff --git a/math/modular_inverse.wiki b/math/modular_inverse.wiki
new file mode 100644
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+++ b/math/modular_inverse.wiki
@@ -0,0 +1,26 @@
+= Modular Inverse =
+
+A modular inverse is an _x_ such that satisfies the equation of form
+
+A * x = (mod m)
+
+This is derived from a statement in form
+
+A^-1 (mod m)
+
+This is due to the nature of modular operations, and can be shown via the
+following set of steps.
+
+A^-1 = 1/A
+
+A * x = 1
+
+x = 1/A
+
+Therefore, via substiution
+
+A * x = (mod m)
+
+This means that x will be the inverse of A
+
+To solve this, see the [[euclidean_algorithm]]