Question

How do you change $2.9$ into a fraction?

Answer 1

Hint:
To convert the decimal to fraction, the student has to divide by $10, 100, 1000$ depending on the number of digits after the decimal point. For example if there is $1$ digit after the decimal point the student has to divide by $10$, if $2$ then divide by $100$ and so on.

Complete step by step solution:
First step is to determine the number of digits after the decimal point. As we can see that there is only $1$ digit after the decimal point, we will have to divide the given number by $10$.
$2.9 = \dfrac{{29}}{{10}}$
Next step is to simplify the given fraction in terms of its prime numbers and then cancel out the common terms. But we can see from the above sum that $29$ is a prime number so it cannot be reduced further.

Thus $2.9$ can be expressed as $\dfrac{{29}}{{10}}$ in fraction.

Note:
Whenever such a type of sum is asked , the student should first divide the number by $10,100,1000$. This will help in reducing the number much faster. SO if a student has a similar sum but complicated like $3.5 \times \dfrac{{10}}{{70}} \times 4.2$, he/she should not start directly multiplying the number. Instead he/she should first get all the terms in the fraction form and then strike off common terms. THis would be the correct approach to solve such a type of sum.