# Make it possible to write expressions with more than one +, -, * & / without getting it reduced

Aritmometer shared this problem 2 years ago
Not a Problem

I will suggest to make it possible to write expressions in input boxes with more than one +, -, * & / without getting it reduced when using the symbolic option.

When entering a calculation with more than one +, -, * or / the expression gets reduced.

And when entering for example one * and at least one + or -, the multiplication gets calculated and reduced.

Please change this so that nothing in the expression gets reduced.

1

Well it should be possible to make calculations no? How would GeoGebra know whether you want to calculate something or whether you want to put in an exprssion not to be reduced?

1

I thought that was the idea with the “symbolic” option...

Else you could make another option. For example “unreduced expression”.

1

The Symbolic option makes it possible e.g. to show the input as a nice fraction or even root without being reduced, that's true. But how would you prevent students to remove one of the * of +? When writing expressions in an inputbox they aren't calculated as you see in screenshots below. Isn't this what you want (except the interdiction to remove the + or * signs)? So yes in inputboxes expressions aren't reduced, but of course they are in the inputbar (I guessed this was your question).

1

Will the expression also not be reduced if you enter for example: 2 * 3 * 4 ?

Which kind of variable is the input box connected to ?

When have this been possible or which version are you using ?

1

Here's an example of a simple number, but it works the same for functions etc. As you see the number is calculated in the Algebra View, but remains an expression in the inputbox. It works as well in Classic 5 and 6 and I'm working now in version 609. Don't forget to check the option Symbolic in the Algebra tab of the input box. This is a Version 6 screenshot.

1

Okay, then it must have been made since I downloaded a new version in August and suggested it in a post without getting any feedback related to the suggestion.

1

I have installed the latest version of GeoGebra 5 classic for Linux from the beginning of October.

In this version I still get 6 * 4 when writing 2*3*4 in a input box that is connected with a function and set to Symbolic.

So for me it seems it haven’t been changed in this version...

Also as I can’t write it in my other post called “Show * between letters”, I can add that it is possible, but only when the letters doesn’t match defined variables.

1

I have just downloaded and installed the latest version of GeoGebra 5 Classic in Windows 10 and tried to write 3^2 - 4 * 2 * 3 in a input box which is set to Symbolic.

When the input box is connected with a number variable, 3^2 - 4 * 2 * 3 is shown in the input box. But in the Algebra view, the value of the variable is -15. And this cannot be used to check if a student has inserted the integers correctly in a formula as the student just could write the correct result.

If instead the input box is connected to a function variable, 9 - 24 is shown in the input box.

When wanting GeoGebra to check if a student has correctly substituted letters with integers in a formula, the content of the connected variable has to be the same as the shown content in the input box.

I would therefore very much appreciate if you somehow could make it possible.

A solution could be to make a special formula variable or make it possible to choose an option so that the expression of a number or function variable won’t be reduced.