diff --git a/src/blocks/numsToLetters.js b/src/blocks/numsToLetters.js
index f02881c..e403fa1 100644
--- a/src/blocks/numsToLetters.js
+++ b/src/blocks/numsToLetters.js
@@ -26,10 +26,10 @@ module.exports =  {
     .map((num)=>((num%52)+52)%52)
     .map((num)=>{
       if(num < 26){
-        asciiOffset = 97;
+        var asciiOffset = 97;
       }
       else{
-        asciiOffset = 65 - 26;
+        var asciiOffset = 65 - 26;
       }
       return num + asciiOffset;
     })
diff --git a/src/blocks/util/coPrime.js b/src/blocks/util/coPrime.js
index e53450d..56e2e2b 100644
--- a/src/blocks/util/coPrime.js
+++ b/src/blocks/util/coPrime.js
@@ -9,8 +9,8 @@ function getFactors(num){
 }
 
 function coPrime(a, b){
-  aFactors = getFactors(a);
-  bFactors = getFactors(b);
+  var aFactors = getFactors(a);
+  var bFactors = getFactors(b);
   var common = aFactors.filter((factor)=>(bFactors.indexOf(factor) > -1));
 
   return (common.length == 0);
diff --git a/src/blocks/vigenereDecode.js b/src/blocks/vigenereDecode.js
index 479a270..0b05729 100644
--- a/src/blocks/vigenereDecode.js
+++ b/src/blocks/vigenereDecode.js
@@ -21,7 +21,7 @@ module.exports =  {
     return cipherText
     .split("")
     .map(require("./util/toNum.js"))
-    .map((int, pos, ints)=>{
+    .map(function(int, pos, ints){
       if(Number.isInteger(int)){
         this.i++;
         return (int + 26 - keyNums[this.i%key.length])%26;
diff --git a/src/blocks/vigenereEncode.js b/src/blocks/vigenereEncode.js
index 513caa8..1ed5b2f 100644
--- a/src/blocks/vigenereEncode.js
+++ b/src/blocks/vigenereEncode.js
@@ -17,14 +17,14 @@ module.exports =  {
   output: true,
   execute: function({plaintext, key}, elem){
     var keyNums = key.split("").map(require("./util/toNum.js"));
-    
+
     return plaintext
     .split("")
     .map(require("./util/toNum.js"))
     .map(function(int, pos, ints){
       if(Number.isInteger(int)){
         this.i++;
-        return val =  (int + keyNums[this.i % key.length]) % 26;
+        return (int + keyNums[this.i % key.length]) % 26;
       }
       else{
         return int;
diff --git a/src/typeConversion.js b/src/typeConversion.js
index 222e21a..e815aec 100644
--- a/src/typeConversion.js
+++ b/src/typeConversion.js
@@ -7,7 +7,7 @@ module.exports = {
   },
   number: function(input){
     if(isNaN(parseInt(input))){
-      throw "Invalid input type - should be a string.";
+      throw "Invalid input type - should be a number.";
     }
     return parseInt(input);
   }