You can easily improve your skills in mental arithmetics! Mencal is an app help you with your mental arithmetic.There are many tutorials and smart test engine in this app.Enjoy it.

#-------------Addition--------------#
• Two-digit number like ab+ba
• Three-digit number like abc+cba
• Two fractions like 1/a+1/b
• Two fractions like (a-1)/a + (b-1)/b
• Sum of first n odd numbers
• Sum of first n even numbers

#------------Substraction-----------#
• Two-digit number like ab-ba
• Three-digit number like abc-cba
• m-n if m+n=100,1000,10000...
• Two fractions like 1/a-1/b
• Two fractions like c/a-c/b
• Two fractions like (a-1)/a-(b-1)/b

#-----------Multiplication----------#
• Same ten's digit, 1's sum is 10
• Same ten's digit, 1's sum isn`t 10
• Same 1's digit, ten's digits sum is 10
• Same 1's digit, ten's digits sum isn`t 10
• two-digit number ab×cc (a+b=10)
• ab×ccc.....c (a+b=10)
• Multiply by 11
• 2-digit number if 1's digit is 1
• 2-digit number if tens place digit is 1
• 2-digit number ×2-digit number(universal)

#--------------Division-------------#
• Divide any number by 5
• Divide any number by 25
• Divide any number by 125
• Divide any 3-figure number by 9

#--------------Square---------------#
• Square numbers made up of 1's
• Square numbers made up of 3's
• Square numbers in the 90's
• Square numbers ten`s digit is 0
• Square a number ending in 25
• Square numbers made up of 6's
• Square numbers made up of 9's
• Square a number ending in 1
• Square a number ending in 5
• Square a number ending in 9
• Square numbers in the 10's
• Square numbers in the 40's
• Square numbers in the 50's