diff --git a/lib/README.md b/lib/README.md
index 62d10cf..f8b45e8 100644
--- a/lib/README.md
+++ b/lib/README.md
@@ -1,14 +1,27 @@
 Equation
 ========
-
 Solve math expressions or create equations for repeated and complex Math tasks.
 
 ```javascript
 // solve
-console.log(Equation.solve('4 * lg4 ^ 3')); // 32 
+console.log(Equation.solve('4 * lg4 ^ 3')); // 32
 
-// equations
+// equation
 let sphereArea = Equation.equation('4 * PI * r^2');
 
 console.log(sphereArea(5)); // 314.1592653589793
 ```
+
+API
+===
+####solve(expression: String)
+Takes a math expression and evaluates it, returning the result.
+
+###equation(expression: String)
+Takes a math expression containing variables, returning a function which
+replaces the variables with given arguments, and solves the expression.
+
+TODO
+====
+* Equation solver
+* More tests