Josh Lury 
A Creative Approach to Teaching Calculation [PDF ebook] 

Calculations are the gateway to outstanding learning in mathematics, but many people struggle with the step-by-step procedures of calculation methods. This book motivates learners by using pattern, practical hands-on and real-world activities that engage the curiosity, and the innate mathematical ability, of pupils and teachers.
The material is addressed to teachers, and takes into account recent developments in teaching and the new Primary curriculum. It is based around practical classroom activities, with clear and concise explanations of the power of different calculation methods and images. It is designed to be quickly accessible to teachers who want to find engaging activities for their pupils.