Syntax ERROR
Casio Casio Calculator
Severity: MinorWhat Does This Error Mean?
Syntax ERROR means the calculator cannot understand the expression you entered. You have a missing bracket, an operator in the wrong place, or an incomplete expression. Press the arrow key to go back to your expression and fix it.
Affected Models
- Casio fx-991EX
- Casio fx-991ES Plus
- Casio fx-82ES
- Casio fx-85GT
- Casio fx-9860GII
- Casio fx-CG50
Common Causes
- Missing closing bracket or parenthesis
- Two operators next to each other (e.g. 5 + * 3)
- Empty brackets ()
- Expression ending with an operator (e.g. 5 + )
- Using a function without an argument (e.g. sin without a number)
How to Fix It
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Press the left/right arrow keys to return to your expression.
The cursor appears at or near the error location. Look for the mistake and edit it directly.
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Count your opening and closing brackets.
Every ( needs a matching ). Casio calculators do not auto-close brackets — you must close them all manually.
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Check for double operators.
5 + * 3 is invalid. 5 * 3 is correct. Also check for operators at the start or end of the expression.
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Make sure every function has an argument.
sin, cos, log, ln all need a number or expression after them. sin() without a value inside causes Syntax ERROR.
Frequently Asked Questions
How do I clear a Syntax ERROR?
Press AC to clear everything and start over, or press the arrow keys to go back to your expression and edit it. Editing is usually faster than retyping the whole expression.
Does the Casio show where the syntax error is?
Yes. When you press the arrow key after a Syntax ERROR, the cursor jumps to the approximate location of the problem. The error is usually at or just before the cursor position.