The skills acquired through mental math calculations make it easy both for students sitting examinations and for people in other spheres of life. Mental math addition is one of the most basic skills in this domain and is not too difficult to learn. The strategies available differ according to levels of ability.
An example of a simple addition strategy involves the addition of several-digit numbers. The easiest way to do such sums is moving piles. It involves altering big numbers into forms we can work with. 34+56 may seem challenging but when you move 4 from the first value to the second, you have 30+60=90. Changing the values to 10s and 5s is the best way to make it seem easy.
Another trick involves the addition of big numbers from the left side instead of from the left. This makes it rather easy to add up even four figure digits using mental math addition. Think about 4795+5678 as 4+5, 7+6, 9+7 and 8+5. Just note the second value of each two-digit answer and add 1 to the previous one. That means that you will first have 9363 as your answer and then add 1 to the first three values to give 10473.
When the sum involves addition of columns, it is not really necessary to write it down. Simply add up the value of one column at a time.
More taxing mental math addition challenges may involve adding numbers in a series. The sum of numbers in a 10-number series always comes to the value of the 7th number X11. When a series comprises doubles (e.g. 2, 4, 8…), the sum of all its value is double the last figure minus the first value. In the above sequence therefore just take 8X2-2=14. The trick is especially helpful with long series containing high values.
Addition of sequences is another challenge that not many think can be solved mentally. If for instance you are required to add all the numbers in a sequence between 1 and 31, use this method: get the product of that final value (31) and half the next value (32/2) i.e. 31X16 and that gives you the answer. You can simplify the multiplication part of it as well and get the answer easy.
If on the other hand you are required to do a mental math addition of all the numbers between two numbers e.g. if you are given 5 and 19 as the values, get their sum and multiply it by half their difference +1. ([8+19=27], [19-8=11], [11+1=12], [12/2=6], [6X27=146]). That is the sum of all the numbers between 5 and 19.