We're currently building a site that contains many mathematical equations and using MathML to show these.
Quite a few of these equations contain unknown values. For example:
12 + ? = 23 2 * ? = 10
The reason for this is to help young children better understand mathematical equations.
However, I am unsure as to how I am supposed to express these unknown values in MathML. At the moment I have simply been using:
<mtext>?</mtext>
to show a blank number.
Is this method acceptable or is there a standard practice I'm unaware of?