How can we use math to understand--and solve--challenges in our world? In "What We Do When Fairness Fails Us," Moises, Marissa, and Astrud realize that a specialized high school uses a lottery for admission that prevents many qualified students from attending. As they research how lotteries work, they come across videos by Federico Ardila, a mathematician who explains concepts like randomness and probability and how they apply to our everyday lives. Join Moises, Marissa, and Astrud as they learn from Federico how they can use math--and their voices--to change unfair systems and help people get the opportunities they deserve. "What We Do When Fairness Fails Us is part of the Powerful Mathematicians Who Changed the World book series." Edited by Christa Jackson and illustrated by Estrella Bascuñan, the "Powerful Mathematicians Who Changed the World" book series centers on underrepresented mathematicians we do not typically hear or learn about in school. By reading the stories, you and your child will gain insight into the remarkable work of these mathematicians, learn about their mathematical contributions, and become more intrigued and see yourself more as learners and doers of mathematics. You and your child will see how mathematics helps us understand the world in which we live through these captivating stories. You will witness your own mathematical brilliance. This series will features book for elementary, middle, and high school audiences.