Question

How do you write $ - \dfrac{5}{8}$ as a decimal?

Answer 1

Hint:
Even though there is a negative sign, the student should ignore it till the end and then just insert the negative sign at the end of the sum. Though this problem is straightforward, one trick to solve such sums is by converting them to the nearest $100s.$ By doing this the student will not have to sit and divide the numerator and the denominator. Chances of going wrong are also very less. The first step is to find the nearest $100s$ for $8$. After that, the student has to multiply the numerator and denominator by the same number so that the denominator has $100$ or it’s multiple. After this step, the student will just have to input the decimal point to get the final answer.

Complete step by step solution:
The first step is to find the nearest multiple of $100$.
Since $8$ is close to $100$, we will convert $8$ to $100$ by multiplying it with $12.5$
Multiplying by $12.5$ to both numerator and denominator, we get
$ - \dfrac{5}{8} = \dfrac{{ - 5}}{8} \times \dfrac{{12.5}}{{12.5}}.............(1)$
$\dfrac{{ - 5}}{8} = \dfrac{{ - 62.5}}{{100}} = - 0.625............(2)$

From equation $2$ we can say that the decimal value for $ - \dfrac{5}{8}$is$ - 0.625$.

Note:
This numerical is very simple if it is done by this method. Otherwise, in the case of a complex numerical for example $ - \dfrac{{395}}{{250}}$, if the student sits and divides the numerator and denominator, he may consume a lot of time. On the contrary, just multiplying the numerator and denominator by a common multiple would solve the sum faster. Thus the students are always advised to bring the numerator in terms of its nearest $100th$multiple and then convert the number to decimal. Also, the chances of making errors by following this method are less compared to direct division.