diff --git a/src/adagrams.js b/src/adagrams.js
index 7ec5afc7..b6252cf6 100644
--- a/src/adagrams.js
+++ b/src/adagrams.js
@@ -1,15 +1,151 @@
+const letterPool = {
+  A: 9,
+  B: 2,
+  C: 2,
+  D: 4,
+  E: 12,
+  F: 2,
+  G: 3,
+  H: 2,
+  I: 9,
+  J: 1,
+  K: 1,
+  L: 4,
+  M: 2,
+  N: 6,
+  O: 8,
+  P: 2,
+  Q: 1,
+  R: 6,
+  S: 4,
+  T: 6,
+  U: 4,
+  V: 2,
+  W: 2,
+  X: 1,
+  Y: 2,
+  Z: 1,
+}; 
+
+const scoreChart ={
+  A: 1,
+  B: 3,
+  C: 3,
+  D: 2,
+  E: 1,
+  F: 4,
+  G: 2,
+  H: 4,
+  I: 1,
+  J: 8,
+  K: 5,
+  L: 1,
+  M: 3,
+  N: 1,
+  O: 1,
+  P: 3,
+  Q: 10,
+  R: 1,
+  S: 1,
+  T: 1,
+  U: 1,
+  V: 4,
+  W: 4,
+  X: 8,
+  Y: 4,
+  Z: 10,
+
+};
+
 export const drawLetters = () => {
-  // Implement this method for wave 1
+  // initial drawLetters, cloneLetterPool, letters
+  const drawLetters = [];
+  let cloneLetterPool = {...letterPool};
+  let letters = Object.keys(cloneLetterPool);
+
+  // for loop 10 times
+  for (let i=0;i<10;++i){
+    // get random letter in the pool
+    let randomLetter = letters[Math.floor(Math.random()*letters.length)];
+    // check the value of letter in the pool
+    if (cloneLetterPool[randomLetter]>0){
+      cloneLetterPool[randomLetter]--;
+      drawLetters.push(randomLetter);
+      };
+  };
+  return drawLetters;
 };
 
 export const usesAvailableLetters = (input, lettersInHand) => {
-  // Implement this method for wave 2
-};
+  // set new object
+  let lettersInHandFreq = {};
+  // count letter frequency
+  for (let letter of lettersInHand) {
+    if (letter in lettersInHandFreq) {
+      lettersInHandFreq[letter] += 1;
+    }else{
+      lettersInHandFreq[letter] = 1;
+    }
+  };
 
+  // check input letter
+  for (let cha of input) {
+    if (cha in lettersInHandFreq) {
+      if (lettersInHandFreq[cha] >= 1) {
+        lettersInHandFreq[cha] -= 1;
+      } else{
+        return false;
+      }
+    } else {
+      return false;
+    };
+  }
+  return true;
+}
 export const scoreWord = (word) => {
-  // Implement this method for wave 3
+  // initial wordLength and score
+  let wordLength = word.length;
+  let score = 0;
+  // get the score for wordLength < 7
+  if (wordLength < 7) {
+    for(let cha of word.toUpperCase()) {
+      let chaScore = scoreChart[cha];
+      score += chaScore;
+    }
+    return score;
+  } else{
+    // get the score for wordLength >= 7
+    score = 8;
+    for(let cha of word.toUpperCase()) {
+      let chaScore = scoreChart[cha];
+      score += chaScore;
+    }
+    return score;
+  }
+  
 };
 
 export const highestScoreFrom = (words) => {
-  // Implement this method for wave 4
+  // Initial hightestScore and winningWord
+  let highestScore = 0;
+  let winningWord = "";
+  //iterate each word and get the score
+  words.forEach((word) => {
+    let score = scoreWord(word);
+  // if the  score more than highestScore sign on the new data
+    if (score > highestScore){
+      highestScore = score;
+      winningWord = word;
+    } else if (score === highestScore) {
+      //if the scores are same, choose the word, which is length is 10
+      if (word.length === 10 && winningWord.length != 10) {
+        winningWord = word;
+        // //if the scores are same, choose the length is smaller.
+      } else if (word.length < winningWord.length && winningWord.length != 10){
+        winningWord = word;
+      } 
+    }
+  });
+  const winner = {word: winningWord, score:highestScore};
+  return winner;
 };
diff --git a/test/adagrams.test.js b/test/adagrams.test.js
index 1a0dc94e..52ce0659 100644
--- a/test/adagrams.test.js
+++ b/test/adagrams.test.js
@@ -120,7 +120,9 @@ describe("Adagrams", () => {
     });
 
     it("returns a score of 0 if given an empty input", () => {
-      throw "Complete test";
+      expectScores({
+        "": 0,
+      })
     });
 
     it("adds an extra 8 points if word is 7 or more characters long", () => {
@@ -133,7 +135,7 @@ describe("Adagrams", () => {
     });
   });
 
-  describe.skip("highestScoreFrom", () => {
+  describe("highestScoreFrom", () => {
     it("returns a hash that contains the word and score of best word in an array", () => {
       const words = ["X", "XX", "XXX", "XXXX"];
       const correct = { word: "XXXX", score: scoreWord("XXXX") };
@@ -145,7 +147,7 @@ describe("Adagrams", () => {
       const words = ["XXX", "XXXX", "X", "XX"];
       const correct = { word: "XXXX", score: scoreWord("XXXX") };
 
-      throw "Complete test by adding an assertion";
+      expect(highestScoreFrom(words)).toEqual(correct);
     });
 
     describe("in case of tied score", () => {