b' New Challenge Mathematics is a series on Mental Mathematics forClasses 18 based\non the NCERT guidelines for primary and middleschool. The books have been\ndesigned as practice material todevelop and hone mathematical and problemsolving\nskills instudents. \n\nHighlights * Sharpens mathematical skills through interesting activities,\n puzzles and games\n * Includes Skill Builder which helps students apply their skills in\n different situations '