Greetings...

I've been told the Murderous Maths books from the Horrible Books folks can be grouped in the following fashion, and I'm wondering if someone could give me guidance on which book(s) to introduce first to my 9yo...

Murderous Maths : Essential Arithmetricks (2008 New Edition)
Murderous Maths : Numbers, the Key to the Universe
Murderous Maths : Murderous Maths (2008 New Edition)
Murderous Maths : More Murderous Maths (2008 New Edition)


Murderous Maths : Desperate Measures: Length, Area and Volume (2008 New Edition)
Murderous Maths : Vicious Circles and Other Savage Shapes
Murderous Maths : Mean and Vulgar Bits
Murderous Maths : Do You Feel Lucky? The Secrets of Probability


Murderous Maths : Phantom X
Murderous Maths : Fiendish Angletron
Murderous Maths : Perfect Sausage and Other Fundamental Formulas


Murderous Maths : Codes, How to Make Them and Break Them
Murderous Maths : Professor Fiendish's Book of Brain-Benders
Murderous Maths : Kakuro and Other Fiendish Number Puzzles


Thanks for input!