It's very hard to crack the competitive exams without solving the simplification faster. Let's crack the exam by learning the tricks to solve the simplifications sooner. Some of the basic tricks for arithmetic operations are disclosed below. It's time to play with numbers when you have the ability to solve the speed mathematics by knowing each trick and applying those tricks in competitive exams. You must know these tricks in order to approach your unique style.
Let's begin with the first method of approach for these types of numbers multiplication.
Section - I
Examples:
Question no.1 : 12 * 18 = 216
Everyone uses the basic approach to find out the answer now let's use a different kind of approach with a mental calculation.
Two basic things you should keep in mind to proceed with this method.
i) check the one's digit number of the two integers summing up it should be 10.
ii) check the ten's digits where it should have the same number.
As you see here these two cases satisfied were summing up of 8 and 2 gives 10. Then also it has the same ten's digits.
Coming to the solution, all you have to do it to simply multiply 8 and 2 and put 16 at the end.
Now take the next number of the ten's digit i.e. it's 2 and multiplies with 1.
So you get 2, then put that number in front of the 16 i.e. 216.
Hope this clarifies.
Kindly use this same kind of approach for these questions.
Question 2 : 83 * 87
Question 3 : 64 * 66
Question 4 : 93 * 97
Question 5 : 41 * 49
Section - II
Now we will see another set of questions with different sets of numbers.
Question no 1 : 22 * 82 = 1804
Now, this can be done with simple mind calculation without pen and paper.
Two rules you should keep in mind while following this simple trick.
i) The one's digit must be the same number
ii) Summing of ten's digits should be 10.
If these two conditions are satisfied then we can proceed with this trick.
Kindly multiply the one's digit from the numbers 2 * 2 = 04
Kindly make a note that we shouldn't make a mistake by simply multiplying and putting it as 4 it should be 04.
The next step is to multiply 2 and 8 in the ten's digit and sums up with the one's digit i.e. 2 * 8 =16 + 2 = 18
Concatenation of these steps will result in 1804.
Some of the questions to solve for this type of method.
Question 2 : 86 * 26 = 2236
Question 3 : 73 * 33
Question 4 : 64 * 44
Question 5 : 92 * 12
Section III
This is a simple section where anyone can simply use any of the above sections to solve these types of questions.
Question no 1: 55 * 55
Now we can apply both methods which I have defined in the above sections and easily we can find the answer.
So check for the conditions in section 1 the answer will be 3025.
Similarly, section II condition also satisfies.
So kindly approach appropriately.
Section IV
In this section let's learn about hundred's types of numbers.
Take this example 103 * 104
+3 +4
10712
Here it is, another trick to follow with
Any numbers which are greater than 100 as of this numbers 103 and 104. We have to simply multiply 3 and 4 keeping the number 100 as a base.
Now 3 * 4 = 12 put this number at the end.
So which gives 107 on adding 103 and 4 or you can add 104 and 3.
Both results are the same.
Now concatenation of these numbers gives 10712.
Question 2 : 111 * 112
Here we have to perform one basic step to complete the trick.
I hope this clarifies.
Question 3 : 108 * 109
Section V
In section IV, we learned when numbers are greater than 100 when multiplied we can follow that step but say for example when we want to multiply two numbers like 101 and 98 then this step won't work out.
So to proceed with this type of number we have to follow the steps mentioned below.
Take an example
Because of considering 100 as a base, we have to put -1.
Only for this type of case like when negative numbers arise while solving.
Now, 99 if found. Then the second thing is to multiply +2 and -2 which gives -04.
Where we have to subtract this from 100.
So we will get 100-04 = 96.
99 96
Concatenation of this we will get the answer as 9996.
