Singh Tricks

Addition When we were at school, we have been taught how to sum two or more numbers together by using the right to left approach. With this method, you first sum the decimal part of the number, then you move to the hundreds and so on. This works good on paper, but it’s a pain when you’re doingmental calculations. Fortunately, the solution is very easy. Left to right approach Instead of using a right to left approach, we can start from the left and move to theright. Take the following example: Usually, you would first sum up 4 to 45, and then and 30 to the result. But by using the left to right approach, you first sum up 30 to 45, and then you add 4 to the result. Although this exampleis very simple, you’ll see theadvantages of this method as you start to use it. If you’re working with three digits numbers, the process is the same. For example 45+34 now, (45+30)=(75+4)=79 This example is a bit more complicated than the previous one, yet it’s very easy to solve using the left t

Quickly find percentages *. To find out the 15% of a number, divide it by 10 andthe add half of it. *. To find out the 20% of a number, divide it by 10 andmultiply the result by two. *. To find out the 5% of a number, divide it by 10 andthe divide it by two.

Multiply by 9 To multiply by 9, simply multiply by 10 and then subtract the number itself. For example 9*11 now, 9*11=10*11=110-11=99

Multiply any two digits numbers with the same first digit and the second digit that sums up to 10 Let’s say that you want to multiply 42 and 48 together. Notice that they both start with 4, and that the sum of their second digit is 10. In this case there’s a simple rule that you can use to find their product. Simply multiply the first digit (4) for the nexthigher number (5) and then append the product of their second digits. For example 1).42*48 now, (4*5)(2*8)=2016 2).91*99 Now, (9*10)(1*9)=9009 Note that if the product of the second digits is below ten, you have to add a 0 in front of it.

How to multiply any two digits number by 11 Let’s say that you want to find the product of 36 and 11. One way to find it would be to multiply 36 by 10 and then add 36 on the result. There is, however, a simple trick that’ll do the job for any two digits number. To find out the result, write the first digit followed by the addition of the first and second digit, followed by the second digit. For example 36*11 now, 3(3+6)6=396 Example: What happens if the sum of the two numbers is bigger than 9? In this case you add 1 to the first number, followed by the last digit of the addition of the two numbers, and then again you add the second number For example 87*11 now, 8(8+7)7=957

Square any two digits number that ends with 5 Calculating the square of a number below 100 is extremely simple. If you wantto find the square of 25 for example, you simply have to take the first digit (2), multiply it for the next highernumber (3), and then add 25 to the result. For example 1). 25*25 now, (2*3)25=625 2). 75*75 now, (7*8)25=5625

Multiplying by 11 is easier when adjusting the rule for multiplying by 9. Just think of11 as (10+1) So 436 × 11 = 4360 + 436 = 4796…that’s the simpler way of explaining why the digits add up to each other like youwrote: 4360 + 436 —– 4796

How to multiply any two digits number by 11 Let’s say that you want to find the product of 36 and 11. One way to find it would be to multiply 36 by 10 and then add 36 on the result. There is, however, a simple trick that’ll do the job for any two digits number. To find out the result, write the first digit followed by the addition of the first and second digit, followed by the second digit. Example: What happens if the sum of the two numbers is bigger than 9? In this case you add 1 to the first number, followed by the last digit of the addition of the two numbers, and then again youadd the second number

Multiplying by 11 is easier when adjusting the rule for multiplying by 9. Just think of11 as (10+1) So 436 × 11 = 4360 + 436 = 4796…that’s the simpler way of explaining why the digits add up to each other like youwrote: 4360 + 436 —– 4796

Link to previous multiplication post 7. Squaring other 2-digit numbers Let’s say you want to square58. Square each digit and write a partial answer. 5×5 = 25. 8×8 = 64. Write down 2564 to start. Then, multiply the two digits of the number you’re squaring together, 5×8=40. Double this product: 40×2=80, then add a 0 to it, getting 800. Add 800 to 2564 to get 3364. This is pretty complicated so let’s do more examples. 32×32. The first part of the answer comes from squaring 3 and 2. 3×3=9. 2×2 = 4. Write down 0904. Notice the extra zeros.It’s important that every square in the partial product have two digits. Multiply the digits, 2 and 3, together and double the whole thing. 2×3x2 = 12. Add a zero to get 120. Add 120 to the partial product, 0904, and we get 1024. 56×56. The partial product comes from 5×5 and 6×6. Write down 2536. 5×6x2 = 60. Add a zero to get 600. 56×56 = 2536+600 = 3136. One more example: 67×67. Write down 3649 as the partial product. 6×7x2 = 42×2 = 84. Add

1. Multiplying by 9, or 99, or 999 Multiplying by 9 is really multiplying by 10-1. So, 9×9 is just 9x(10-1) which is 9×10-9 which is 90-9 or 81. Let’s try a harder example: 46×9 = 46×10-46 = 460-46 =414. One more example: 68×9 = 680-68 = 612. To multiply by 99, you multiply by 100-1. So, 46×99 = 46x(100-1) = 4600-46 = 4554. Multiplying by 999 is similar to multiplying by 9 and by 99. 38×999 = 38x(1000-1) = 38000-38 = 37962. 2. Multiplying by 11 To multiply a number by 11 you add pairs of numbers next to each other, except for the numbers on the edges. Let me illustrate: To multiply 436 by 11 go fromright to left. First write down the 6 then add 6 to its neighbor on the left, 3, to get 9. Write down 9 to the left of 6. Then add 4 to 3 to get 7. Write down 7. Then, write down the leftmostdigit, 4. So, 436×11 = is 4796. Let’s do another example: 3254×11. The answer comes from these sums and edge numbers: (3)(3+2)(2+5)(5+4)(4) = 35794. One more example, this one involvi

When you learned how to do math in school, you probably learned how to do it from right to left.  One of the secrets to doing fast math tricks in your head is to learn how to solve mathematical problems from left to right. Actually, learning this mathtricks method is not very difficult.  In fact, your brain is already hard-wired for solving math problems from left to right; you have spent years reading left to right, correct?  Well, then your brain is trained to think from left to right – so lets try it with some simple addition problems! Addition Example 1 45 + 38 This is a very easy problem, and it is even easier if you solve it from left to right.  First, break down the number 38 into it’s tens and ones: 30 + 8 Now add the numbers in this fashion: 45 + 30 75 + 8 = 83 So the full breakdown of theproblem looks like this: 45 + 38 = 45 + (30 + 8) Once you have the problem in this format, it is much easier to solve. Addition Example 2 384 + 467 Once again, to solve this pr

Age Calculation Age Calculation Tricks: Step1 : Multiply the first number of the age by 5. (If <10, ex 5, consider it as 05. If it is >100, ex: 102, then take 10 as the first digit, 2 as the second one.) Step2 : Add 3 to the result. Step3 : Double the answer. Step4 : Add the second digit of the number with the result. Step5 : Subtract 6 from it. Answer: That is your age.

When you learned how to do math in school, you probably learned how to do it from right to left.  One of the secrets to doing fast math tricks in your head is to learn how to solve mathematical problems from left to right. Actually, learning this mathtricks method is not very difficult.  In fact, your brain is already hard-wired for solving math problems from left to right; you have spent years reading left to right, correct?  Well, then your brain is trained to think from left to right – so lets try it with some simple addition problems! Addition Example 1 45 + 38 This is a very easy problem, and it is even easier if you solve it from left to right.  First, break down the number 38 into it’s tens and ones: 30 + 8 Now add the numbers in this fashion: 45 + 30 75 + 8 = 83 So the full breakdown of theproblem looks like this: 45 + 38 = 45 + (30 + 8) Once you have the problem in this format, it is much easier to solve. Addition Example 2 384 + 467 Once again, to solve this pr