1. You gave too many inputs to a command. MicroWorlds doesn’t know what to do with this extra input. Here are some examples:
print 3 4 Print will take the 3 as input but
MicroWorlds doesn’t know what to do
with the 4.
fd 50 10 Fd will take the 50 as input but
MicroWorlds doesn’t know what to do
with the 10.
2. An instruction began with something that reports a value. Every instruction must begin with a command. Here is an example:
5 + 16
I don't know what to do with 21
5 + 16 reports 21. You have to tell MicroWorlds what to do with this number. Do you want to show it in the Command Center?
show 5 + 16
21
The arithmetic signs (+, -, >, <) are reporters, like the primitives color, pos, and shape. They "say" something (the result of the operation, the current position of the turtle).
Show, print, and forward are commands. They don't report anything. They just "do" something.