In my JSX, I'm mapping through API data and then display the values, from the object array.
Except in my JSX, I want to add two prices together, from my data.  Something like this.
<div className="right">
  <p>
    from <span>£{(phone.priceInfo.hardwarePrice.oneOffPrice.gross + phone.priceInfo.hardwarePrice.oneOffPrice.gross)}</span> upfront cost
  </p>
</div>
However, let's say phone.priceInfo.hardwarePrice.oneOffPrice.gross === 10, then in my DOM, the following returns £10+£10, rather than £20.
How do I do an addition sum, in my JSX?
 
    