A number may be expressed in binary form in SmileBasic by using the prefix &B. For a numeric literal, &b is converted to &B, so for example PRINT &b100 gives 8, but PRINT VAL("&b100") gives Syntax error (VAL). Another difference between the way &B is handled in literals and in VAL is that VAL does not require any digits to follow: PRINT &B makes a Syntax error, but PRINT VAL("&B") gives 0.
If more than 20 bits follow the prefix in a literal, the system will generate a Syntax error, even if the first bits are 0 and the value is within SmileBasic's range. If more than 20 bits follow the prefix in a string passed to VAL, the system instead generates an Overflow (VAL) error, again even if the value is within SmileBasic's range. The values &B10000000000000000000 to &B11111111111111111111 give negative numbers in the standard 2s complement sense, and &B10000000000000000000 in particular is a value which exposes some bugs in SmileBasic.
In some instances, it is not necessary to put a space between the end of the literal and the following operator, e.g. PRINT &B1+&B1 will give 2 as expected, but in others, it is necessary, e.g. PRINT &B1OR&B1 gives the confusing result 101, and the assignment V=&B1OR&B1 generates a Syntax Error. The commands PRINT &B1 OR&B1 and V=&B1 OR&B1 will give the expected results.
The prefix for hexadecimal values is &H.