diff --git a/basic/42-merkle-distributor-airdrop/contracts/redpacket/HappyRedPacket.sol b/basic/42-merkle-distributor-airdrop/contracts/redpacket/HappyRedPacket.sol
index 7d09936b3..0fee70c5a 100644
--- a/basic/42-merkle-distributor-airdrop/contracts/redpacket/HappyRedPacket.sol
+++ b/basic/42-merkle-distributor-airdrop/contracts/redpacket/HappyRedPacket.sol
@@ -77,7 +77,7 @@ contract HappyRedPacket is Initializable {
         require(_number < 256, "At most 255 recipients");
         require(_token_type == 0 || _token_type == 1, "Unrecognizable token type");
 
-        // require minium 0.1 for each user
+        // require minimum 0.1 for each user
         require(_total_tokens > 10**(IERC20(_token_addr).decimals() - 1) * _number , "At least 0.1 for each user");
         
         uint256 received_amount = _total_tokens;
@@ -139,12 +139,12 @@ contract HappyRedPacket is Initializable {
             if (total_number - claimed_number == 1)
                 claimed_tokens = remaining_tokens;
             else{
-                // reserve minium amount => (total_number - claimed_number) * 0.1
+                // reserve minimum amount => (total_number - claimed_number) * 0.1
                 uint reserve_amount = (total_number - claimed_number) * minium_value;
                 uint distribute_tokens = remaining_tokens - reserve_amount;
                 claimed_tokens = random(seed, nonce) % (distribute_tokens * 2/ (total_number - claimed_number));
 
-                // minium claimed_tokens for user is 0.1 ; and round the claimed_tokens to decimal 0.1
+                // minimum claimed_tokens for user is 0.1 ; and round the claimed_tokens to decimal 0.1
                 claimed_tokens = claimed_tokens < minium_value ? minium_value : (claimed_tokens - (claimed_tokens % minium_value));
             }
         } else {
diff --git a/defi/Alchemix/contracts/Transmuter.sol b/defi/Alchemix/contracts/Transmuter.sol
index ff7d56ab3..5540ae0ec 100644
--- a/defi/Alchemix/contracts/Transmuter.sol
+++ b/defi/Alchemix/contracts/Transmuter.sol
@@ -141,7 +141,7 @@ contract Transmuter is Context {
             // NOTE: if last deposit was updated in the same block as the current call
             // then the below logic gates will fail
 
-            //calculate diffrence in time
+            //calculate difference in time
             uint256 deltaTime = _currentBlock.sub(_lastDepositBlock);
 
             // distribute all if bigger than timeframe
@@ -297,7 +297,7 @@ contract Transmuter is Context {
         // empty bucket
         tokensInBucket[toTransmute] = 0;
 
-        // calculaate diffrence
+        // calculaate difference
         uint256 diff = pendingz.sub(depositedAlTokens[toTransmute]);
 
         // remove overflow
diff --git a/defi/Alchemix/contracts/TransmuterB.sol b/defi/Alchemix/contracts/TransmuterB.sol
index 3dacc9b8f..2703b2914 100644
--- a/defi/Alchemix/contracts/TransmuterB.sol
+++ b/defi/Alchemix/contracts/TransmuterB.sol
@@ -274,7 +274,7 @@ contract TransmuterB is Context {
             // NOTE: if last deposit was updated in the same block as the current call
             // then the below logic gates will fail
 
-            //calculate diffrence in time
+            //calculate difference in time
             uint256 deltaTime = _currentBlock.sub(_lastDepositBlock);
 
             // distribute all if bigger than timeframe
@@ -325,7 +325,7 @@ contract TransmuterB is Context {
         _;
     }
 
-    /// @dev checks that the block delay since a user's last action is longer than the minium delay
+    /// @dev checks that the block delay since a user's last action is longer than the minimum delay
     ///
     modifier ensureUserActionDelay() {
         require(block.number.sub(lastUserAction[msg.sender]) >= minUserActionDelay, "action delay not met");
@@ -469,7 +469,7 @@ contract TransmuterB is Context {
         // empty bucket
         tokensInBucket[toTransmute] = 0;
 
-        // calculaate diffrence
+        // calculaate difference
         uint256 diff = pendingz.sub(depositedAlTokens[toTransmute]);
 
         // remove overflow
diff --git a/defi/Alchemix/contracts/TransmuterEth.sol b/defi/Alchemix/contracts/TransmuterEth.sol
index 51ebb18e8..43ed8acb8 100644
--- a/defi/Alchemix/contracts/TransmuterEth.sol
+++ b/defi/Alchemix/contracts/TransmuterEth.sol
@@ -275,7 +275,7 @@ contract TransmuterEth is Context {
             // NOTE: if last deposit was updated in the same block as the current call
             // then the below logic gates will fail
 
-            //calculate diffrence in time
+            //calculate difference in time
             uint256 deltaTime = _currentBlock.sub(_lastDepositBlock);
 
             // distribute all if bigger than timeframe
@@ -326,7 +326,7 @@ contract TransmuterEth is Context {
         _;
     }
 
-    /// @dev checks that the block delay since a user's last action is longer than the minium delay
+    /// @dev checks that the block delay since a user's last action is longer than the minimum delay
     ///
     modifier ensureUserActionDelay() {
         require(block.number.sub(lastUserAction[msg.sender]) >= minUserActionDelay, "action delay not met");
@@ -475,7 +475,7 @@ contract TransmuterEth is Context {
         // empty bucket
         tokensInBucket[toTransmute] = 0;
 
-        // calculaate diffrence
+        // calculaate difference
         uint256 diff = pendingz.sub(depositedAlTokens[toTransmute]);
 
         // remove overflow