Calculation Tricks are your best allies when it comes to multiplying numbers in SBI PO, IBPS and SSC CGL Exam and getting to the correct answer in the least amount of time possible.
Questions in the Quantitative Aptitude section of all competitive exams like SBI PO, IBPS, SSC CGL not only need you to have strong but also have some calculation tricks up your sleeve, that help you save time. If you are one of those who skips a question just because it needs you to multiply then this calculation trick is especially for you!
So here is the 7th calculation trick and we’ll once again discuss a short cut about multiplying numbers. This trick will make sure that you are able to multiply numbers with numbers from 11- 19.
Ok! now before you rush to kill us for explaining what you were taught in 3rd grade in school let us tell you why exactly we are discussing about multiplying numbers! Certainly no question in any competitive exam will directly ask you to multiply two numbers but almost every other question will have you to multiplying numbers with numbers that lie between 11- 19.
Example of Multiplying Numbers from 11 to 19 with the Given Number
What is the answer for-
(i) 1732 x 11 (ii) 1598 x 12 (iii) 38916 x 14 (iv) 43172 x 19
A. 19882, 18176, 444824, 920268
B. 17992, 20176, 644734, 720268
C. 19052, 19176, 544824, 820268
D. 18052, 21176, 588424, 840268
Conventional Method of Multiplying Numbers from 11 to 19 with the Given Number
So what is your usual reaction on reading a question like this? You first multiply 1732 with 11 using the regular method where 1 is first multiplied with 2, then with 3, then 7 and so on… then you go to the next line, and start multiplying 1732 with 1 once again. Only this time you write the numbers in the tens place then add them and get your answer. You follow this method for multiplying all the numbers!
Smart Method of Multiplying Numbers from 11 to 19 with the Given Number
Let’s simplify this very complicated method of multiplying numbers for you and also help you save some time in the process.
1732 x 11
Multiply the number in the units place with the other number in the units place. In this case multiply 1 with 2
For the second digit, multiply 1 with 3 and add the previous digit that is 2 in this case, so it will be 5
Move on with the remaining digits multiplying with 1 and adding the previous digit in the same way. In case there is a two digit number, carry it forward and add it.
Let’s try multiplying next two numbers – 1598 x 12
Multiply the number in the units place with the other number in the units place. In this case multiply 2 with 8
Now in this case 1 will be carried forward. We’ll multiply 2 with 9, and add 8 to it. We get 26, to this we will add the carried forward 1 and so we get 27. Now 7 will be written and 2 will be carried forward.
Similarly carry on with the entire number and you’ll get the answer.
Isn’t this way more simple and quick! This method can be used for multiplying numbers from 11 to 19 by this method.
Use this calculation trick while multiplying numbers now-
Question 1: 34568 x 19 = ?
1) 656792 2) 566792 3) 700792 4) 665792
Question 2: 76432 x 13 = ?
1) 993116 2) 993616 3) 100616 4) 103116
Do tell us in the comments section how long you took in multiplying these numbers.