Mi band 5 does not support calling the math keyboard directly on the bracelet. Mi band 5 is mainly used for health monitoring, motion tracking, message reminding and other functions. Its screen is very small and there is no mathematical keyboard input interface.

If you need to carry out mathematical calculation or input mathematical formulas, it is recommended to use other devices, such as mobile phones, tablet computers or computers, to carry out mathematical calculation and input with corresponding mathematical applications or software.

It should be noted that different mathematical applications or software may have different usage methods and interfaces, and the specific ways of calling the mathematical keyboard may also be different. You can choose the math application that suits you, and refer to its official documentation or user's guide to learn how to call the math keyboard on the corresponding device.