It depends whether you make him do very overt 'work', or whether you do lots of things which are fun, educational but not 'schooly'.
For example, there are lots of online Maths games which are 'mathsy' - but equally, any board game with dice or money or strategy, any type of number puzzle, and anything that requires him to add up how long something will take, or how much it will cost, is maths.
Equally, he may hate reading books, but does he also hate reading recipes (especially foer unusually delicious cakes or biscuits...) or instructions, or directions, or the guidebook for somewhere you are going?
He may hate writing, but what about lists or labelled diagrams or letters to you to request something? Where might he really want to go durig the summer>? Say you might take him there, if he works out costs, timings, directions, can tell you all about what is there and writes you a letter to persuade you to go there....
Or can he create websites or videos using something like Adobe Sparks? Typing the content is again a form of writing? Science experiments, cooking, distances on cycle routes? Trips to places that are e.g. historical but also child-friendly, or hands-on science places like WeTheCurious or the Science Museum?