Fractions are an expression of ratios.
The ratio 5/6 is the same as the ratio 10/12.
How is 5/6 equivalent to 10/12?
2*5/2*6
= 10/12
======You just use a form of one (2/2 in this case ) to convert fractions.
The same way 1/100 is equal to 2/200 is equal
divide numerator and denominator by 2 in 10/12
(10÷2)/(12÷2) = 5/6
and multiply numerator and denominator by 2 in 5/6
(5×2)/(6×2) = 10/12