how to use onclickup with Contact Form 7

I like to achieve this with contact form 7, I have a text field which onkeyup would multiply inputed value in its text field and populate another text field, I’ve been able to achieve this in an html form using onkeyup, the question now is, how do I achieve this via contact form 7 in wordpress?

here’s a sample of my html form

<p>Amount: <br />
<input type="text" name="number" value="" onkeyup="number_times_10.value=this.value*170"></p>

<p>Naira Equivalent: <br />₦<input type="text" name="number_times_10" disabled> </p>