For starters, the “simple machine” topic is typically better suited for the primary grades.  This text is geared for grades 5-9, with an older girl visual on the cover.  The title certainly appeals to the procrastinators of that older developmental age.  If science projects can be done in an hour or less…great!!  However, on closer inspection, some materials needed to perform the experiments might not be able to be found within the hour…such as a toy wagon or a spring balance.  Also, many of the formulas included require the students to have prior knowledge, as many terms used are not definied.  Although the design layout of the book is attractive, it is not very user friendly.