Entering and viewing binary numbers

Using:
uVision 5
*** Using Compiler 'V5.06 update 6 (build 750)', folder: 'C:\Keil\uVision5\ARM\ARMCC\Bin'

I'm trying to make a variable equal to a binary number, something like:

unsigned char Number = 0b00001111;

The IDE doesn't show any issues on the screen, but the compiler comes back with this error:

..\ZCU\source\code\Debug_rW.c(67): error: #19: extra text after expected end of number

How do I get round this?

Secondly, I which to view that "Number" in a watch window as a binary number, is this possible? I can only see Hex and Decimal as an option.

Many thanks for any input.

Regards, R