Sideways Arithmetic from Wayside School (Wayside School #2.5)

Blurb

Why does elf + elf = fool? How many meals will Miss Mush, the lunch teacher, have to cook for the food to taste as bad as it smells? This book is packed full of brain teasers and maths puzzles and all the wacky pupils from Wayside School to help you find the logical solutions to all the problems. Kids will have fun solving more than 50 mathematical brain teasers while reading this great collection of stories from Wayside School--where students laugh as much as they learn.