Put down the calculator
We have to do simple arithmetic every day, whether we like it or not. And most of the time, we do not carry a calculator around with us. Thus, being able to calculate simple math problems in our heads is a pretty useful ability. It is not only a way to impress your friends, but is also a stimulating activity that helps keep your mind sharp.
There are a lot of different tricks to help you do both simple and more advanced math in your head. Here are two of the most useful:
Rearrange the numbers
Let’s start with something simple. Let’s say you have to calculate the following sum:
9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1
You can start adding 9 + 8 to get 17, and then add 17 + 7 to get 24, and so forth. However, if you look more closely at the example you will notice that there’s an easier way. Each of the outer pairs of numbers adds up to 10 – a nice, friendly number. 9 + 1=10, 8 + 2=10, 7 + 3=10, and 6 + 4=10. Therefore, the whole thing boils down to adding 10 + 10 + 10 + 10 + 5, which makes 45. It’s a useful technique you can use on different tests like the SAT and IQ tests, which often have similar math problems that can seem tedious and complicated at first, but can easily be solved if you spot the pattern.
Look for friendly numbers
Let’s say you have to find the product of 23 and 31. It may seem intimidating to try doing this in your head, but there’s a trick to it that can help you. It’s much easier if you have to multiply numbers ending in 0’s, right? Hence, we can try to break up the multiplication as follows:
23 x 31 = (20 + 3) x (30 + 1)
Then, relying on the basic properties of multiplication we get the following:
- 20 x 30 = 600
- 20 x 1 = 20, and 600 + 20= 620
- 3 x 30 = 90, and 620 + 90 = 710
- 3 x 1 = 3, and 710 + 3 = 713
Notice that we only had to remember one number between steps, which makes it much easier to do the multiplication.
___________________________________________________________________________________________
This brain improvement technique has been adapted from the popular book Mind Performance Hacks: Tips & Tools for Overclocking Your Brain by Ron Hale-Evans. In it, you'll find even more techniques
to help you improve your brain, including how to:
|