Tiny Basic...

 
Sequence
Assignment
Conditional
Iteration
Subroutines
Input/Output
 
100 REM Sample TinyBasic program...
110 GOTO 410
410 PRINT "Think of a number between 1
420 INPUT N
440 GOSUB 200
450 PRINT "The square root of ",N," is
200 REM Newton's method to find the squ
210 LET L=1
230 LET R=(L+H)/2
250 IF M=N THEN RETURN
310 GOTO 230