1. As a backup mobile phone: Take the old mobile phone as a backup mobile phone, which can be used when the main mobile phone has problems or needs to be repaired to ensure smooth communication.
2. As children's toys: download some games or educational software suitable for children from old mobile phones, so that children can learn while playing.
3. as a home monitoring device: install some monitoring software on the old mobile phone, which can be used as a home monitoring device to monitor the situation at home.
4. as a music player: use an old mobile phone as a music player, and you can connect it to a stereo or headphones to enjoy high-quality music.
5. as an e-book reader: download some e-book reading software from your old mobile phone, which can be used as an e-book reader to read your favorite books anytime and anywhere.
6. as a smart home control center: install some smart home control software on the old mobile phone, which can be used as a smart home control center to control smart devices at home.
7. as a donation or recycling: if the old mobile phone is no longer usable or its functions are old, you can consider donating or recycling it to make better use of it.