Flutter Web Scrapping: How to get a data between <> and <>

Question

Used Third Package List: http.dart, dom.dart, parser.dart

Question: As you can see there is 16 between <span class= 'temperature_text> and , I want to get 16. How can I get that 16?

HTML CODE

<div class='temperature_text'>
<strong>
<span class='blind'>Current Temp</span>
16
<span class='celsius'>°</span>
</strong>
</div>