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Using the concept of place value to your advantage:

Updated: Oct 1, 2021

By Pranomita Shom


There are various mathematical problems, which can be quite easy to solve if we use the concept of place value to our advantage. Here, we will explain how to do so with an example.


  • The rightmost digit of a 6-digit number is 1. If we put it before the other digits, making it the leftmost digit, the new number obtained will be 1/3 of the original number. Find the original number.


Let's consider the original number as x

Firstly, we need to remove the 1 at the right.


So,


(x−1)/10

This gives us a 5-digit number without "1" as its last digit.


Here, we have utilized the fact that the 1 has a place value of 1


Then,


{(x − 1)/10} + 100000


Here, we have utilized the fact that to shift the 1 in the very left, we need to add:


the digit x place value


= 1 x 100000



So, now we can form an equation using the information that the new number obtained is 1/3 of the original number.


{(x − 1)}/10 + 100000 =x/3

=>(x/3) −{(x − 1)}/10=100000

=>(7x + 3)/30 = 100000

=> 7x = 2999997

∴ x = 428571


Consequently, we can conclude that the concept of place value is one of the various ways of making problem solving an easy task.

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