This book shows a very simple approach to Calculus that can be used as an introduction for quite young children.
Prerequisites are basic graph work, an understanding of what a gradient is and a basic knowledge of algebra.
The book shows that the subject can be taught in a very simple way and without the usual use of complex terminology and symbolism.
The standard calculus notations are however introduced here as well (later in the book).
This means that the teacher or parent can connect with the standard approach as appropriate for their class or child.