Mathematics – Already feeling the cold sweats approaching, aren’t you?
Maths has been known to give even the geekiest of kids nightmares, especially during exams. However, just like every Indian teenager, Maths is just misunderstood for the most part. The conceptual knowledge that you acquire during your school years is essentially applied analytically throughout the rest of your education journey. However, that being said, a little help never hurts. So to help improve your strained relationship with one of the most important subjects of your entire academic life, we bring to you a list of tricks that will bring out the mathematical Houdini hiding behind that disgruntled expression of yours:
Addition of big numbers
No, we are not taking you back to elementary school. Addition of big numbers right off the bat might be a tad difficult at times. However, rounding off the numbers to the nearest multiple of 10 will simplify the process. Once you get the result for the said calculation, you just have to subtract the total value you added to round off the numbers.
For example, while adding 647 and 748,
– Simply add 650 + 750
– This will give you 1400
Now, to get the actual result, simply subtract the value we added to round off the respective numbers –
Value added : (650-647) + (750-748) = 3 + 2
Thus, the final answer is 1400 – 5 = 1395
Subtracting any number from 1000
The easiest way to subtract any number from 1000 is to subtract each individual number from 9 and the last one from 10.
For example –
1000 – 557
9 – 5 = 4
9 – 5 = 4
10 – 7 = 3
And your answer = 443
Multiplying any number by 5
When multiplying an even number by 5, simply break down the number in half and add 0 to it.
For example, for 5 x 4:
Half of 4 is 2, adding a 0 to it gives you 20.
When multiplying an odd number by 5, the process is a little different:
For example, if you are trying to multiply 5 x 3,
Step 1: Subtract 1 from the said number (3-2) = 1
Step 2: Half the number thus derived. (half of 2 = 1)
Add 5 to this digit. (= 15)
The final number is your answer = 15.
Often you will need to figure out whether a certain number is divisible by a particular number or digit. To save time and unnecessary efforts on your part, here’s a list of fun tricks to help you figure your way out of that particular dilemma:
A number will be divisible by
– 10, if the last digit is 0
– 9, if the sum total of the digits of the number is evenly divisible by 9
– 8, if the last three digits are evenly by 8 or are 000
– 6, if the number is even and the sum of the digits is divisible by 3
– 5, if it ends with the digit 5 or 0
– 4, if it ends in 00 or a two digit number evenly divisible by 4
– 3, if the sum total of the digits is evenly by 3
– 2, if it ends in 0, 2, 4, 6, 8.
And to make it an even better deal for you, we are giving away something really special. You get a
Bonus Mathematics Magic TRICK !
Ever met someone who freakishly could always guess the answer to a random calculation they made you do, all in your head, without ever asking for any details? Have you always wondered how they did it?
Well, you are about to become one of those people, yourself!
Step 1: Ask someone to choose a number, any number in their heads.
Step 2: Ask them to double that number
Step 3: Then, ask them to add 9 to the result
Step 4: Ask them to subtract 3
Step 5: Ask them to divide it by 2.
And for the final step, ask them to subtract the original number. The answer will be 3. Every time!
Go on, impress your unsuspecting friends! And don’t reveal your method, after all a true magician never reveals his secrets.