Can someone show me the methodology on how to convert $1.2794$ to a percentage form?
If I multiply it by $100$, I get $127.94$%, which is the correct answer. I'm not really sure 'why' I multiplied it by $100$, furthermore, do I multiply every decimal by $100$ if I want to convert it to a percentage, or is there a rule?
Another one is how do I convert $2 + \frac{4}{15}$ to a percentage form?
This might seem quite elementary, but I haven't been taught a methodological way in solving these.
On
The percent sign ($\%$) is the symbol used to indicate a percentage, a number or ratio as a fraction of $100$.
What that means is that you can replace the sign $\%$ by $\times\frac{1}{100}$. For example, $1.2794 = 127.94 \times \frac{1}{100} = 127.94\%$.
So strictly speaking, when you want to write the number as a percentage, you don't really multiply it by 100, you express it as a multiplication with $\frac{1}{100}$. But when you want to calculate it, of course, you can just multiply the number by 100 as you did. Just don't write that in a test.
For $2+\frac{4}{15}$, it's the same. $2+\frac{4}{15} = (200 + \frac{400}{15})*\frac{1}{100} = (200 + \frac{400}{15})\%$. After that it's your choice to leave it in this form or write it as a irreductible fraction ($\frac{3400}{15}\%$), or as an approximate number ($226.6666...\%$)...
Yes, you are right. To convert real numbers to percentage form, you need to multiply by $100$.
That is due to the definition of the percentage notation.
Let $x$ be the percentage representation of $1.2794$.
Then $1.2794 = \displaystyle\frac{x}{100}$ (by definition)
Hence, $x = 1.2794 \times 100 = 126.94\%$.
To convert fractions (proper or improper) to percentage, you can first convert them to their decimal representation and then convert to percentage as outlined above.
$$2 + 4/15 = 2 + 0.2666 = 2.26666 = 226.66\%$$