What's 7 4 9? nNeeded more than five seconds? This can be better With Mental Maths you can playfully improve your mental calculation skills through various exercises. Image puzzles are an incentive to carry on practicing.nnChoose math exercises from many categories:n Basic Arithmeticn Division with Remaindern Percentage Calculationn Reading and Writing Roman Numeralsn Common Multiples and DivisorsnnMoreover, there aren 4 Difficulty Levelsn an adjustable Time Limitn Exercises in order of operations and paranthesesn Exercises to practice specific Multiplication Tablesn Statistics for multiple usersnnWhile the first difficulty level is designed for elementary school students, the higher levels are a challenge even for experienced calculators. Everyone reaches their limit when a time limit is set, at the latest nnnMental Maths has been developed by a mathematician from the University of Hamburg in collaboration with mathematics teachers in grades 110.