Short Tricks for Squares, Cubes and Multiplications
September 18, 2021 2021-09-17 16:17Short Tricks for Squares, Cubes and Multiplications
The questions related to squares, cubes and multiplications are a part of the quantitative aptitude section of the competitive exams like the SSC exams and the IBPS bank exams like the IBPS Clerk, IBPS PO and IBPS SO exams. These questions are time consuming as you are required to apply mathematical concepts to solve them.
But when you are appearing for competitive exams, you need to have a few tricks which you can use while solving questions based on the squares, cubes and multiplications. These short tricks can help the candidates to solve such questions accurately and in a much lesser time.
What are the Short Tricks for Squares, Cubes and Multiplications?
While appearing for the competitive exams, it is important for the candidates to know some short tricks for squares, cubes and multiplications. We will see these tricks one by one in this article.
1. Short tricks for squares
There are two main methods in which you can calculate the squares of the given numbers— the 100 method or the 50 method.
a. 100 method
In this method we assume 100 as the base for calculating the squares of the given numbers. This method can be used for numbers between 80 to 100, 100 to 120 and 71 to 79. For example, if you want to find the square for 90, first calculate the difference between the number and the base, which is 10 in this case. Then subtract this difference from the number, on which you will get 80. The last step is the square of the difference; here it will be the square of 10, which is 100. So the final answer will be, 8100.
b. 50 method
In this method, 50 is considered as the base. This method can be used for numbers between 50 to 70, 30 to 50 and 71 to 79. For example, if you want to find the square of 46, you have to follow the following formula:
25 − difference from base_square of the difference, so the square of 46 will be,
25 − 4_16 = 2116.
2. Short Tricks for cubes
If you manually calculate the cube of any number, it can be time consuming, but if you follow the following steps, you can easily calculate the cube of any number in a shorter amount of time.
Step 1: note the cube of the tens place, that will make your fist digit, then the next three digits will be the ratio of the digits in the number and their exact proportion,
Step 2: multiply the second and third digit by 2
Step 3: on adding the two rows, you will get your answer.
2. Short Tricks for Multiplications
There are a number of short tricks which can be used for multiplication.
a. Multiplication of numbers having 5 at their units place
Type 1: Same numbers
15 × 15 = (1 × 2)_25 = 225
Type 2: numbers having a difference of 10
25 × 35 = (2 × 4)_75 = 875
Type 3: numbers having a difference of 20
25 × 45 = (2 × 5)_125 = 1125
Type 4: numbers having a difference of 30
25 × 55 = (2 × 6)_175 = 1375 (1 from 175 has to be transferred to 12)
b. Multiplication of different numbers
Type 1: when difference between two numbers is even
Multiplication = (middle number)2 − (difference/2)2
Type 2: consecutive number multiplication
Multiplication = Square of small number + small number
By using the above approaches for solving squares, cubes and multiplications you can solve the quantitative aptitude section much quickly which will prevent you from spending too much time on one section and you would be able to concentrate on other important sections of the exam as well.