I wish I had this book when I was studying in 5th Standard. The Cartoon Guide to Physics is easily the best 'text book' on physics. The educators will disagree, of course. Education, for some strange reason, has turned out to be not-for-fun activity. Pity!
How deep is the Cartoon Guide?
Counter question: What do you know of Pseudo-forces? The first time when I understood this concept I was well into college. The Cartoon guide explains the concept in 11 sketches. And does a good job of it. The chapter is called "Some Forces are Fictitious".
And by the time you complete the chapters of Electricity and Magnetism, believe me, you will be ready to shred your child's prescribed text books.