Well done Ms. Alexander! A teenage love story reminiscent of The Fault in Our Stars. But...I didn't like The Fault in Our Stars but absolutely adored Unknown Variables. I was drawn to this book because of the math connotations but quickly fell in love with ALL the characters in the book. From the nerdy math group to the cranky old lady to the friendship between two young girls, not to mention the love story. You couldn't help but feel touched by each character and appreciate the clumsiness of teenage love. Would give it more than 5 stars if I could (and I'm pretty picky with my books.) RECOMMEND!