Check students' answer with % sign in math input

I’d like to check students’ math input which includes a percent sign (475%). I set the correct answer to

correct= this.latex=`475\%` 
correct: correct

But when I tried with student preview, desmos automatically added the word “of” after %. I tried

initialLatex: `\%`

which prevents the auto-text “of”. But when I entered 475 in front of % in student preview, it still reported incorrect. I also tried “%” in Latex code without backslash and it still didn’t work. Could anyone help?