Type description of 'money' in mysql

The instructions are as follows:  
money   holds the currency value data type, which ranges from -922337203685477.5808 to +922337203685477.5808   has a maximum length of 8 bytes.  
smallmoney   holds the currency value data type, ranging from -214748.3647 to +214748.3647   with a maximum length of 4 bytes.  
As you can see, you can consider using the double type, because double has 8 bytes, while float has 4 bytes,