A brand new book.  There is a small residue from the price sticker at the top left corner.

Whole numbers, decimals, signed numbers, integers, order of operations, open number expressions, equations, metric measurement, circle geometry. Uses the check and double check concept whereby children first perform the skill, then perform it twice more to ensure the skill has been mastered before moving on. This series is by level versus grade, making them ideal for remedial or enrichment.