&preHooks = `math`
<label for="math"><span>[[!+op1]] [[!+operator]] [[!+op2]]?</span><span class="error">[[+reg.error.math]]</span></label> <input type="text" name="math" value="" /> <input type="hidden" name="op1" value="[[!+op1]]" /> <input type="hidden" name="op2" value="[[!+op2]]" /> <input type="hidden" name="operator" value="[[!+operator]]" />
<label>[[!+fi.op1]] [[!+fi.operator]] [[!+fi.op2]]?</label> [[!+fi.error.math]] <input type="text" name="math:required" value="[[!+fi.math]]" /> <input type="hidden" name="op1" value="[[!+fi.op1]]" /> <input type="hidden" name="op2" value="[[!+fi.op2]]" /> <input type="hidden" name="operator" value="[[!+fi.operator]]" />
<label>[[!+reg.op1]] [[!+reg.operator]] [[!+reg.op2]]?</label> [[!+reg.error.math]] <input type="text" name="math:required" value="[[!+reg.math]]" /> <input type="hidden" name="op1" value="[[!+reg.op1]]" /> <input type="hidden" name="op2" value="[[!+reg.op2]]" /> <input type="hidden" name="operator" value="[[!+reg.operator]]" />
&placeholderPrefix=``