Five rational numbers between 021 and 024 are 21.1, 21.5, 22, 22.5, and 23. Rational numbers are those that can be expressed as a fraction of two integers, and all of these numbers fit that criteria. **

To transfer Minecraft PE worlds, you can use a file transfer method such as using a cloud storage service like Dropbox or Google Drive to upload the world from your device and then download it onto another device. Another option is to use a file manager app to locate the Minecraft PE worlds folder on your device and then transfer the world file to another device using a USB cable or Bluetooth. You can also use the "Export" feature within the game to save the world as a .mcworld file and then transfer it to another device. **

To play Minecraft PE online, you can either join a public server or create a private server and invite your friends to join. To join a public server, simply select the "Play" option from the main menu, then choose "Servers" and select a server from the list. If you want to play with friends, you can create a private server by selecting "Create" from the main menu, then choose "New Realm" or "New Server" and invite your friends to join using the server address. Additionally, you can also join multiplayer games through Xbox Live or LAN. **

To transfer a Minecraft PE world, you can use a file manager app on your device to locate the world folder. Once you have found the world folder, you can copy it to a cloud storage service like Google Drive or Dropbox. Then, you can download the world folder onto your new device and place it in the appropriate Minecraft PE directory. Finally, open Minecraft PE on the new device and you should see the transferred world available to play. **

To play online in Minecraft PE, you can either join a server or play with friends through a local Wi-Fi network. To join a server, you need to select the "Play" option from the main menu, then choose "Servers" and select a server to join. To play with friends over a local Wi-Fi network, make sure all devices are connected to the same network, then select the "Friends" tab in the game and invite your friends to join your world. **

To calculate the tangent of 021 on a calculator, you would first need to ensure that your calculator is set to the correct angle mode (either degrees or radians). Then, simply input "tan(21)" or "tan(21°)" into the calculator and press the "equals" button. The calculator will then display the tangent of 21 degrees, which is approximately 0.3894. **

Online payments can be secure if proper security measures are in place. This includes using secure websites with encryption, using trusted payment processors, and being cautious with sharing personal and financial information. It's important to look for the "https" in the website URL and a lock symbol in the address bar to ensure the website is secure. Additionally, using strong and unique passwords for online accounts can also help enhance security. **

To build a secure and affordable wireless charger, one can start by using high-quality components and materials to ensure safety and reliability. It is important to follow industry standards and regulations for wireless charging to prevent overheating and other safety hazards. Additionally, incorporating features such as overcurrent protection, temperature monitoring, and foreign object detection can enhance the security of the wireless charger. Finally, optimizing the design for cost efficiency and using energy-efficient components can help make the wireless charger affordable for consumers. **