This a series of 4 books for Levels 2 to 5 (grade 1 to year 8). As per the title the focus here is on some environmentally friendly mathematics. I should emphasise that the books are not asking you do something additional to your already full maths program but just alter what you were going to do anyway and give it a ‘green’ edge. I co-wrote these with Bob Winters and they were good fun to write. I don’t collect any royalties from the sale of these books but I really enjoyed writing them and they send positive messages about making maths relevant, being more aware of the environment and occasionally getting your kids outside to do some maths. You can still get them (individually or as a series) at a very good price (bargain bin stuff) from the Gould Group.