Science at Home makes a good case for homework and the value of parents' involvement with their children's education, but I'm not sure what sort of parents John Stringer has met.
He assumes a high level of understanding of both maths and language; he also assumes that a garden and a range of reference books are available in most homes. In my experience, work that is sent home has to be straightforward enough for the child to be able to explain the given task. How many people understand the instruction "draw your soil profile"? And what is the "white powder mystery"? I can't imagine many of the parents that I've had contact with discussing "the beauty of the stars" with their children.
The tasks are arranged in sections: life processes, forces, seasons, materials etc. Each has teacher's notes pointing out the main objective of the task. Some safety advice has been given, but some activities would have been better left out altogether, such as the investigation of mouldy bread.
The book claims to be for key stages 1 and 2, and while this applies to the content, the presentation would have to be adapted for KS1. I would be tempted to leave out the section for the teacher's comment on the homework for parents.