Maths is one of my favourite subjects. And do you know that all of Science is based on Maths?
So let’s embrace Maths.
In today’s post (and the video), I am going to share 4 cool Maths tricks for you to make Maths easy.
Trick #1 – Multiplying by 15, fast
Would you like to multiply any two digit number by 15 fast? Let’s do it!
Let’s consider 47 – the two digit number. Now we are going to multiply it by 15.
Step 1 – Add Zero to the end of 47. We get 470.
Step 2 – Divide that number by 2. 470/2 = 235
Step 3 – Add the two numbers you got in Step 1 and 2: 470+235 = 705
You can try this with any number!
Trick #2 – Multiplying by 11, fast
For single digit numbers, multiplying by 11 is easy. 3×11 is 33 and 7×11 is 77.
But when it comes to two digit numbers, it can get tricky!
So here’s how to do it easily.
Pick any two digit number – let’s pick 34.
Now separate the two numbers, by leaving some space between them.
In between the two numbers, perform addition of the two digits. That is 3[3+4]4.
Which means 34. Now put those digits together and that’s your answer 374.
Now what to do if you get a two digit number as a sum in the center? Well, in that case add the number in the tens position to the first digit of the original number.
For example, lets pick 39.
According to the trick we can write this as – 3[3+9]9.
After adding the digits you get 12 in the middle – 39. Now you have to add the 1 in the tens position with 3, while keeping the 2.
That is [3+1]29 and the answer is 429!
Trick #3 – Multiply by 9, fast
This is a cool trick.
Let’s pick a number, say 347.
All you have to do is put a zero at the end of the number – you get 3470. Now subtract the original number from this number.
3470-347 = 3123
What we basically do is multiply the number by ten and subtract it once to multiply it by 9. Makes sense right?
Trick #4 – Find the square of a number that ends with 5
Let’s pick a number that ends with 5, say 75.
Find the number that follows the first digit number.
The number that’s followed by 7 is 8. Now, multiply 7 and 8. We get 56.
And then put 25 in the end – because any number that ends with 5 will have a square that ends with 25.
So the answer is 5625.
That was easy right?
Try out these tricks with different numbers and have fun.
Apply these tricks when you have to work with big and complicated calculations.
Did you find these Math tricks useful? If so, please share this post and the video with your friends.