Maths Outdoors by Mercia Lee and Helen Yorke - this includes 50 exciting ways to develop mathematical awareness outdoors.
Messy Maths by Juliet Robertson - this book offers a rich resource of ideas that will enable you to tap into endless supply of patterns, textures, colours and quantities of the outdoors and deepen children's understanding through hands on experience.
The Little Book of Maths Outdoors - this shows you how you can take popular maths activities, using low cost resources and make them work outside.
Developing Young Children's Mathematical Learning Outdoors by Lynda Keith - provides detailed guidance and practical advice on planning mathematical experiences for young children outdoors.
5o Fantastic Ideas for Maths Outdoors by Kirstine Beeley - this book offers a treasure trove of ideas to support early maths development, using some of the wonderful resources that nature and the elements offer outside.