diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..6f958c6d465 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,29 @@
-## Put comments here that give an overall description of what your
-## functions do
+## cachematrix: Functions to cache matrix inversion
 
-## Write a short comment describing this function
+## makeCacheMatrix sets up the scope for storing cache
 
 makeCacheMatrix <- function(x = matrix()) {
-
+  m <- NULL # initialize cache to NULL
+  set <- function(y) { # changing value invalidates cache
+    x <<- y
+    m <<- NULL
+  }
+  get <- function() x # return original matrix
+  setinverse <- function(inverse) m <<- inverse # set cache value to supplied value
+  getinverse <- function() m 
+  list(set = set, get = get, setinverse=setinverse, getinverse=getinverse)
 }
 
-
-## Write a short comment describing this function
+## cacheSolve takes the list generated by makeCacheMatrix and either populates its cache
+## or returns the cached value
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+  m <- x$getinverse() # returns NULL if not yet cached
+  if (!is.null(m)) {
+    message('cached inverse') # report that returned value is from cache
+    return(m)
+  }
+  m <- solve(x$get()) # uses solve to get inverse of x
+  x$setinverse(m)
+  m
 }