Speedy Math 1 – Addition of Series of Numbers

A lot of girls find math difficult. The more they think so, the less they want to work on it. Fortunately, there are many regulations and “tricks” in math. As soon as they learn the tricks, the math becomes much easier and more enjoyable. For some problems, it’s almost impossible to solve in a short time period without knowing the tricks. Addition of a regular series of numbers is a classic example.

For example, what is the sum of all the numbers from 1 to 20?
It may take a while to add the numbers from 1 to 20 one by one. But it is much easier if the following steps are followed:
Step 1: Find the number of numbers in the series = (last number – first number + 1) =(20 - 1 + 1)= 20
Step 2: Calculate the average of the first and the last number of the series = (20 + 1)/2 = 21/2 = 10.5
Step 4: Calculate the final result = average x number = 10.5 x 20 = 210

This trick can be extrapolated to much more complicated problems. In the exam situations, it’s is practically impossible to solve the problem without knowing the above trick.

For example, what is the sum of all the numbers from 131 to 1997?
Knowing above trick, the problem can be quickly solved as:
(1997 - 131 + 1) = 1867
(131 + 1991)/2 = 1064
Final answer = 1064 x 1867 = 1986488

After some time, you may forget the exact steps described above. In that case, just try the simplest series: 1 + 2 + 3
(3 - 1 + 1) = 3
(3 + 1)/2 = 2
2 x 3 = 6