You can take a sample of pages from different YA novels. Count the words on each page and then find the average. For example, take 5 pages from 3 different novels, count the words, add them up and divide by 15.
To estimate the average words per page in a YA novel, first consider the physical aspects. A larger page size with wider margins will likely have fewer words per page compared to a smaller page with narrow margins. Then look at the font. A larger font will obviously have fewer words per page. You can also look at the density of the text. If there are a lot of short paragraphs and white space, the word count per page will be lower. By observing these factors and comparing to other books you've read, you can make a rough estimate. For instance, if a book you know has 300 words per page and the YA novel you're looking at has a similar layout but a bit more white space, it might be around 250 - 280 words per page.
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Chapter 587, "Has He Also Become a Part of the Play?", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. It opens with Zhao Lang said "thank you," but his eyes reluctantly glanced at Jiang...
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Chapter 886, "Stinky Beggar", is the clearest early answer because it turns Shuiyun's situation into a concrete plot event.
Chapter 685, "Defense Value Skyrockets!", is the clearest early answer because it turns Luo Xingmu's situation into a concrete plot event. It opens with The scene went live on Weibo right then. and closes on How could he not be furious?.
Chapter 682, "Too Conspicuous to Keep Around", is the clearest early answer because it turns Chang's situation into a concrete plot event.
Chapter 753, "Final Judgment", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. It opens with In the decade she had been with Fang Wenzhe, Shu Yan never thought... and closes on But Shu Yan was simply too outstanding..
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