The article "Part-whole numbers and proportional reasoning" is about teaching mathematics in schools. It covers topics like measurement, geometry, numbers, statistics, probability, and algebra. The goal is to help teachers integrate technology into their lessons and cater to the needs of all students. The researchers provide detailed activities and examples to make learning math easier. The book also comes with access to an online tool called Cambridge HOTmaths, which has multimedia resources to help students and teachers understand math concepts better.