Before joining the bounty, you should read the rules of each campaign carefully. A skate is converted to a Token depending on the number of Tokens the project has for the bounty and the number of members participating in that bounty. Usually, a skate is calculated by the total number of bounty tokens divided by the total number of skates at the end of the bounty. So instead of asking questions like this, you should read the information on the bounty topic.