What is the usage of BTCB?
1 BTCB has the same value as BTC, and can be exchange to BTC in binance.com
2 You can buy BTCB in BinanceDEX, current support BNB/BTCB trading pair, and future will be more
3 You can transfer BTCB in Binance Chain, it super fast and low cost
The detail instruction of how to use BinanceDEX in MathWallet:
https://community.binance.org/topic/205/how-to-use-binancedex-with-mathwallet